Let him resent you - she is HIS child and therefore HIS responsibility. She isn't yours to cope with. I think you're perfectly right in insisting he see her outside of your home. Can't he get his mind round the fact that she is no longer allowed there because HE was not coping with her? His own child?

Not your monkey, not your circus... as the saying goes.

Honestly, I think you are dragging out the inevitable. You have DIRECTLY TOLD HIM. You are in therapy to address it. It is just not clicking; he doesn't (or won't) understand HE needs to parent. 

This is seriously affecting your mental health. Make a clean break and move on.

He is in the wrong for not realizing the way he's treating you. For wanting YOU to discipline HIS child. For letting his child act up in your home and not doing a thing about it. He can't throw the raising of his ODD child on you and then get upset that you don't want to do it.

He is in the wrong for not realizing the way he's treating you. For wanting YOU to discipline HIS child. For letting his child act up in your home and not doing a thing about it. He can't throw the raising of his ODD child on you and then get upset that you don't want to do it.

Why would you want to stay with someone who cares so little about you? I would have had NO respect for my DH, had he tried to pawn his kid off on me.

to help with ADD, ODD is MUCH more difficult.   Not certain what to say, but this may be a situation that is not resolvable.  I wish all the best of luck.

Given the child's diagnosis, it may not be resolvable but OH isn't even trying to parent by the sound of it. You have every right to ban her from YOUR home, in exactly the same way that you wouldn't tolerate anyone else there whose behaviour was unnacceptable. When you say visitiation rights every other weekend, does that mean overnight as well and if so, is she no longer allowed to stay?

I banned my OSD as well when her behaviour became too much - best decision I ever made.

You need to take care of yourself and be selfish (leave him or disengage and make him do EVERYTHING for his daughter).

He is the father and your role in her life is at your discretion, whether you want to be involved or hands off is up to you. 

Being a sh!t father would be enough to end the relationship for me. Don't let him make you believe that's how it should be with you doing all the heavy lifting. 
 

If he wants a full time fill in mommy and a bed warmer let him go fishing for a new victim. 

This resulted in a huge blow-up, because I was being unfair, it's costing him money, making his life miserable etc. 

So you're being "unfair, costing him money and making HIS life miserable" but how about you? Where do you factor at in all this? Does your mental well being and sanity not matter to him? You did right by not allowing visitation in your H and if he doesn't step it up and parent can you imagine what his daughter will be like when she's older?.....

He's in for a rude awakening and hope you won't be a part of it when it does.

He does not want to be a parent, and parent his kid. This will not change either.
Then he's mad at you when you make him kind a parent.  You have no choice,   You know what you must do. 

The child is making my life hell.
Your boyfriend is directly responsible for this because he is a crap father.

therapy to try and explain to him why it is vitally important for the PARENT to firmly discipline
He needs therapy to explain that HIS child is HIS responsbility as a parent? What BS. If he didn't want to have kids, he should have taken steps to make sure that didn't happen.

He has so many wonderful qualities, he makes me so happy.
He's a crap parent. He refuses to parent his child. He gets mad at you. He is FAR from wonderful.

BUT. he can't/wont address his child's behaviour, and he resents me 
He resents you because he expects YOU to control HIS child. 

I feel like ending it
DO IT. You're miserable. Your health is suffering. He's a jackass. Life is too short to be this unhappy.

You are dating a big man baby who doesn't want to be responsible for a child he created...please tell me where is the appeal in that?

It's making HIS life miserable? Well, he's clearly told you that HE is the most important person in this relationship, not you and not his child.

You are perfectly correct to insist that he parent his own child. To expect you to do so is so wrong for so many reasons, including wrong for the child.

Take care of yourself. Nobody else is going to.