I am going to come at this from the perspective of the child although I believe our situations are quite different perhaps my perspective can help.

Firstly I would like to say good on you for at least acknowledging your part and trying to apologize. It can't be easy.

My father was the emotionally and physically abusive one and I now haven't spoken to him in close to two years (in part because of his refusal to accept the damage he's done). A fact I actually feel guilty about.

Now my mother- In my case my mother is clearly "not all there" in the emotional stakes which has lead to its own tensions with her but in relating her to my father she may have been the one to step in when he got physical but it still comes down to the fact that he was carrying out this cruelty for 8 years before she actually did anything to put a stop to it. (Leaving.)

She saved me but she was also the one keeping me in that situation.

On top of that often the fights between my father and I began because I was trying to defend her. He would verbally abuse her and she would ignore it leading to me trying to protect her.

No child should have to feel they need to protect a parent. That's not how it's supposed to work.

Perhaps with his fathers death is has really come down to needing someone to blame and you're all that's left. Maybe he feels guilty that he was unable to help his father and needs someone to lash out at.

Or like someone else said maybe he just wants to cut that part of his life out. I know that's a feeling I get often and that a part of me would willing cut my mother from my life if she didn't need me.

I really hope everything works out for you and that at the very least you can find some peace. Good luck