I believe you taking your children and leaving was the best decision for all of you even if at times it doesn't feel that way.
I'm also glad you and the kids are seeking help and working through all of the emotions regarding the situation. And yes, if there is al-anon in your area I'd give that a try as well.
One of the things that helped me depersonalize his addiction was to learn about addiction and addict behaviors. You will learn that he didn't drink at you he drank because he is an alcoholic. And no matter who, what or where he is in life, he will continue to drink until and if he makes the choice to stop. It's hard not to take what they did or said personally but when we learn to detach it becomes easier.
Sounds like he is from a family of dysfunction and alcoholism. If his dad drank himself to death at 42 his family is a family of untreated alcoholism so don't expect much from them on the side of NOT drinking and understanding the issues brought about from drinking.
I am glad you found SR and posted.