I read here and there through your history. I know that it's not helpful to second-guess every decision you've made along the way, so I'll wait for you to tell more of the story rather than question some of the things you did at this time. You look like you're well detached from him and found a way to take care of yourself and your family without quickly driving yourself off the deep end.
I feel sad for him. In a way, I wish you could have let him fall flat on his face... maybe that's what he's needed for the past however many years. On the other hand, there's no law that says you have to do that for him if you feel your kids needed something else from you. And he didn't have to let you come back and take over for him, and he didn't have to let himself get to that state in the first place.
At least he's back on his meds. Sometimes that goes a long way to make you see reality and give you the strength to accept it.
a fine and enviable madness, this delusion that all questions have answers, and nothing is beyond the reach of a strong left arm.