Leed said it well. I agree completely on this.

It is not fair at all taht he holds your past mistakes over you for things unrelated now. It's a form of control. He is using what you did in the past, clearly not something you are currently continuing, to make you feel guilty and as if you have to pay for it indefinitely. That is wrong and I know it's complete manipulation. Blaming you for his faults is horrible in the first place but making it sound as though you damaged him or the relationship beyond repair is ridiculous. If it was so damaging, and he can't let it go, why is he sticking around with you? Because it's not and he knows it, and he's using it to get out of the blame himself for his part in the relationship, his abuse of you, his anger, depression and whatever else.

He refuses to get help and finds excuses not to - what? because it costs money? That is the lamest excuse! he doesn't want to follow through and as long as you let him hold things over your head, he won't. If you want to fix this relationship, you do need therapy together and most likely as individuals, for you -- to learn to stand up and quit apologizing for something long gone.

I feel for you. I've had someone in my life like this and it hurts *hugs*