I'm sure everyone here can relate 100%.
Although my dad was rarely physically abusive, my story is much like yours. He also doesn't believe he's an alcoholic, despite a professional diagnosis in 1985. He's a functioning alcoholic, always has been.
Like yours, I think he's started to get worse. In 2011, he left me a dozen hateful voicemails (because I would no longer pick up the phone to talk to him), and I'm pretty sure he was drunk at 10:30 in the morning, which would be the first time I've seen him clearly drunk and out of control.
My kids are older, but they are angry with me for refusing to take them to family holidays. My parents have both slapped or tried to slap the younger kids, but the kids themselves either don't remember, or don't seem to get that this isn't a normal way for grandparents to treat their grandchildren.
I, too, have some very negative emotions about my mother's refusal to leave my dad. I can understand in the early 70s, when nobody divorced. But by 1985, when he was forcibly removed from the house by police for domestic assault? When divorce had become more acceptable? When her family was there to support her?
I can only tell you what I have done, and that's to step away. I don't go near my family. Yes, that brings on its own problems. Now I'm the Bad Daughter for 'not talking to my parents and sisters.' Yet I would have been the Bad Daughter for something else, anyway. It's causing trouble with my kids who are angry with my decision. But repeatedly going back and showing my kids by my own behavior that I will accept being a doormat, being yelled at and mistreated by my siblings and father--that also would have caused trouble, as they learned they could do it, too. (Honestly, the older ones expose themselves repeatedly to the toxicity and are learning it, anyway, but at least not by my actions.)
I continue to pray and seek peace in my own life. I continually re-focus on remembering God gave me a life to use for better or worse. I try to put good in the world and live with integrity, and accept that there are some things I simply have no control over, including my children's decisions.
But I am satisfied with my decision to stay away from toxic, belittling, raging people.