Do you want your own children? If so, I'd divorce this man, because he cannot or will not give you something that you want that is huge (at least it is to me). I would not have married my husband if he hadn't been willing to have a child with me, and if he changed his mind about it after we married I would have divorced him. There are things I won't compromise on, and having children of my own was one of them.

He also is not standing up for you with either his kids or the grandparents, which is unacceptable.  HE is the problem there.  He should be more worried about you and your feelings and needs than he is about having to spend money IF the grandparents go to court for grandparents' rights. 

Frankly, I have no issue with the skids calling you Kristen. My skids call me by my first name even though I've been in their lives since they were 1 and 4 and there have been times when I've spent more time with them and did more for them than either of their parents.  You are not their mom and you never will be, no matter how many maternal things you do for them.  You just need to accept that. You don't need to accept rudeness, but they may never appreciate what you do for them.  If you need appreciation or to be "mom," then disengage. The things I do for my skids are done to help my husband.  I don't expect the skids to be appreciative, but I expect him to be.

A lot of this is on your husband.  Insist that he do better.

and my step kids used to call me Crestor.  That was their nickname for me.  The pharaceutical drug.  So it could be worse.  

You definitely have a DH for not standing up to the grandparents.  

Your husband is failing as your protector. There should be no amount of money in this world that would stop him from making sure you are protected and respected. I am sure if the shoe was on the other foot he wouldn't appreciate your family treating him poorly. You should be glad he doesn't want children with you. If you choose to leave you won't have to see him or his children again. 
 

Not that it is right, I would remind the maternal GPs about their daughter and her failures, and tell them to think about that before they even think about speaking about me. As far as his parents, I would tell them to shove it and they should be happy that their son upgraded by being with you. 
 

You might want to think about why you want to be seen as mom to stepchildren that don't appreciate you. It may be to fill the void of not having your own child. If so, go find a better man and fill that void somewhere else!

Amongst other issues, it's clear that you married someone who has very different views on having children. Each person might have hoped that other one will change their mind, but this is the best way to get very, very hurt. Even if you end up getting pregnant and having a baby, even if he comes to love the child, there will always be a low level resentment towards you. Even if you get the step kids to call you "mother", but if you never have the child you long for, you'll have low level resentment towards your DH and the rest of the family. 
This situation is a recipe for a lot of suffering for everyone involved. I'm child free, and I have been in relationships where I was on the brink of being convinced otherwise. I'm glad I didn't give in, or I'd hate my life now, plus these relationships are long gone. 
Get out and make a life with someone who does not need to be convinced, who WANTS to have a child with you, someone who'd consider themselves lucky that you've allowed them to reproduce with you. 

It is only the rest of your life... if you allow it.

So, don't allow it.

You want children and at 40 you are at the tail end of being able to do that safely.  

Whatever you decide, do not have a child with this man.  That would doom both you and your baby to splash around in this shit gene pool for the rest of your lives. Yes. BM was a POS. But... sadly, so is your DH.  He owns nearly as much of the situation as his X does.  Most dispicably, he is manipulating you to have a care giver for his drug babby children and is serving you up to them, his XILs, and his own toxic family as a whipping post.  Stop sacrificing yourself on the alter of Sparental martyrdom to your idiot DH, his dead crackhead X, their spawn, his XILs and your current ILs.  All of them are far from worthy of you. 

If I were you, I would pack my stuff and move on to living your best life. That cannot happen in this marriage.  Your DH is not quality enough or man enough to allow that to happen.

Move on, have your child, and do not accept toxicity in your life.  You can be very selective in the father of your child.  Whether you have that child with a quality mate, or via a donor.  Either option would be far better than risking polluting  your gene pool with your current DH.

Save yourself, save you future child.

Take care of you.

Edited to add: I have no BKs and I am a REAL dad just as you are a REAL mom.  Whether a parent is "real" of not is based on action, not on biology.  As an adult, I do not allow children to call me by my first name.  I also would not mandate that a Skid call me Dad.  We had two significant discussions on this topic when my SS-31 was a child.  His mom and I met when he was 15mos old and married the week before he turned 2yo.

I was the first person he ever called Dad(dy). His choice. He wasn't even 2yo when he made that choice.  

When he was about 5 he came home from a SpermLand visitation and told his mom and I that his SpermGrandHag ahd told him that I was not his REAL dad and that I was only his StepDad.

The conversation went basically like this:

SS: Dad, Gramma says that  you are not my REAL dad and that you are only my StepDad.

Rags:  Son, we have talked about what a StepDad is, what a BioDad is, and what a REAL dad is.  A real dad is the dad that works hard to provide a nice warm and safe home for your family to live in, save vehicles to ride in, good food for you to yeat, good schools for you to go to, a save neighborhood to live in, teaches you to tie your shoes, ride your bike, to read and write, to use the toilet, coaches sports teams, and who loves you and your mom very much.  A real dad can be a BioDad, or a StepDad, or a Grandpa, or an Uncle.

SS: Dad, a StepDad sounds like a real dad to me. Come play with me.

Several years later he came home from a SpermClan visitation telling us that SpermGrandHag would not let him call me dad.

SS: Mom and dad, Gramma says you are only my stepdad and I can't call you dad anymore.

Rags: Son, if you don't want to call me dad anymore that is fine. But no one but you and me can decide that.  Definately not your Gramma (firstname).  I do not let children call me by my first name, so if you no longer want to call me dad you can call me Mr. (Lastname).

SS: I think I will stick with dad. You are my dad.

As her equity life partner his mom would not tolerate anything less than me being an equity parent.  Neither would I. We decided on that very early in our marriage.  If we were going to be equity life partners, we would be equity parents to any children in our marriage regardless of kid bioligy.  As it turned out, he is an only child in our family.  He is the eldest of 4 all out of wedlock spawn by 3 different baby mamas for his pothead POS Spermidiot.

The reality is that if you want to be a mother.. you probably should try to have a child of your own. While you have certainly stepped up and done so much for these kids.. they did have a bio mother.. and it's very difficult to compete with a ghost.  There are your husband's former inlaws.. who lost a daughter.. that probably resent the fact that you are even breathing and above ground.. they have likely looked back on her life with very rosy glasses.. and are clinging to that.. and pushing the narrative on to your step children.  

I am not sure why your husband's parents are a problem too though.. generally.. they should not be as clinging to their dead daughter in law's memory.. and with your good treatment of their grandkids.. should have been more likely to have some more friendly favor there?  was there anything that you think is causing this?

In the end.. you ARE dad's wife.. and not the bio parent of those boys.  If you don't feel that they are giving you reciprocal feelings (names aside.. it doesn't matter if their mother was not perfect.. a dead mom.. they must have some feelings that would be difficult to "replace" her) then don't do what you have been doing.. back off.. no one forces you to volunteer etc.. you can still be nice to them.. but you don't have to take them on as your kids.. and back off more to a support of your husband role as he raises his children.

I'm sorry that those in this family network haven't been more welcoming.. I'm sorry that your husband hasn't insisted his parents be more respectful and hasn't at least put his former inlaws on notice about ill words about you.. even if he didn't ban them.  

And.. I'm sorry you don't get support from other mothers.. that in some cases may be dealing with their own step dynamics.. (maybe they have an ex with a new wife that they resent?)... or are they type that are smug in their value because they pushed out a kid... and you haven't.. so don't measure up? (I have no bios.. some people are like that.. my MIL included).

My advice is that if your relationship is good.. focus on the good of it.. and stop knocking yourself out to impress people that don't care.

Sadly, your expectation to be called "mother" and be treated as such is unreasonable. You cannot force that kind of bond. It's something that happens naturally and not because you do all the motherly things OR that their mother was garbage.

Particularly in strained relationships where a child is longing for a mother who has repeatedly failed him, there is often a loyalty bind. The kid may have an obsessive need to elevate their crap parent onto a pedestal. This may cause them to more fiercely defend the memory of the parent AND a child can create a fantasy about the crap parent having good qualities.

You're up against some serious obstacles to creating a bond with your step children. You may long to love them and be loved as if they were your own, but you're setting yourself up for heartbreak.

If you want children of your own, I hope you can make that happen. Your spouse should be doing more to defend you and protect you from his family and the late bio-mom's family.

((HUGS))

Particularly in strained relationships where a child is longing for a mother who has repeatedly failed him, there is often a loyalty bind. The kid may have an obsessive need to elevate their crap parent onto a pedestal. This may cause them to more fiercely defend the memory of the parent AND a child can create a fantasy about the crap parent having good qualities.

This!!!

Plus, having BM deceased complicates things. Children do not grieve like adults. They are grieving what they wished rather than what they had. They revisit the grief at life events. It's always hiding under the surface. Or on the bracelet. You can't make it disappear. You can only deal with it. 

A concerning part of you post is that you said both sets of grandparents. So it's DH's parents in addition to the BM's parents. This is the a giant DH problem. He needs to shut this down. Have you ever considered couples counseling?

That by now. Nothing is going to change    You excepted this too long.  You DH doesn't respect you, or what you do,  He doesn't love you, if he love you we wouldn't want to see you hurt.   Unfortunately, at 40 you are at a turning point  in your life, 9you have no time to wast.  So do what you want to do. But do it fast before it gets too late. ,

'You have many years to live. Do you really want to live this way