Hi, your story really hit me. I was a friend to an alkie who is 56 and retired and lives with his elderly mother. They fight like cat and dog and he is so verbally abusive to her yet when he's calm he tells her he loves her, makes her tea etc. But mostly it's one fight after another, he claims she's crazy, but I dont think she is. I think she's a first class enabler, tho. His dad is dead, but he finds ways to bring up dad's name, and it's never very nice.
There are a lot of similarities in your story and his, it's almost eerie. I had to cut contact with him as he drove me nuts with his manipulation (he does that very well to his mother) abusive crap and inability to remain sober for more than a few hours. I feel bad for his mom but there's nothing I can do.
I dont really have any good words of advice for you but I'm sure someone else here will.