Wow, you really ARE po'd. OK, so you're totally angry. Here's the thing--happiness is not a zero-sum game. Your happiness does not depend on whether he's happy or miserable.
Your CHILDREN and YOU are what you need to focus on.
Do you have a custody/visitation order in place? If not, get one. If so, follow it to the LETTER. If he doesn't use his time because he's off doing whatever, then that's a shame for the kids, and a burden on you, but it is really irrelevant WHY he is not using his parenting time.
As you are discovering, running after other men to make you feel better doesn't work. And it really isn't fair to this nice guy you've met, when you are in no condition at the moment to be in a relationship, is it?
Are you seeing a therapist? That might help. Are you going to Al-Anon? That might help, too.
Focus on your own recovery and healing. Think of this as a personal emergency. As you said, you are behaving in self-destructive ways. That's good that you recognize that. Reach out for help so you can STOP.
There is happiness to be had in your future. But not until you put this experience in its place.
Hugs,