You Just Described My Brother to a "T"
He's in his early 50's; years ago when I was working treatment I recognized he had the same disease I did (I got sober in 1980), and I tried to set up an intervention to get him to treatment . . .
His then-wife decided to take matters into her own hands, and he acted out, was arrested and wound up in a psych ward. My father flew down and picked him up and put him in a unit here. He stayed three or four days . . .
I've watched 20 years of hell since then for my parents, and what still eats my lunch is that my parents slip back into the same denial and enabling every time he creates a crisis. Worse, I'm the focus of their stuff, and right now I haven't spoken to them for a month because of the way I've been treated (with accusations that I'm the one being disrespectful). I'm unapologetic for taking care of myself (they went to Al-Anon for a long time, but seemed to have missed some things along the way).
The advice about taking care of yourself is golden, and you've got my permission to leave and do whatever it takes to be truly free . . . The question is whether you'll give that permission to yourself...
It's a fatal disease . . . I wish you well, seriously . . . I don't have a lot more old-timer wisdom on this one . . .