The past is past. It's done. You did what you thought was right at the time, all these years, and now we are in today. But honestly, it was never your job to clean up all his messes and you have BIGGER and BETTER things to do with all your energy and efforts than continue to be with someone who does not know how to, or want to, be an equal partner. I think this just provides you opportunities.
I like this.
Regarding your personal emotions during this transition. I found they neeeded expressing. I journalled, I used this forum, trusted friends, and professioanl counselling. NOT the children. Anger and other strong emotions need processing or else the grief becomes trapped and either makes you sick or comes back to bite you on the bum months or years later.
Welcome to SR.