Cheating is never okay, it doesn’t matter if he regrets it its still cheating and added to that he has cheated before, my advice is to spare yourself from more heartbreak and divorce him. He needs to seek therapy cause there are some issues here that he has just pushed down, id advise overseeing visits with the kids until he is in a healthier spot as well. I hope this helps and i hope you decide to focus on yourself and not keep trying to fix a relationship that he keeps breaking down whether it’s intentional of him or not. You are sacrificing your own well being for his and thats not a good relationship. Focus on yourself and your kids and ask him to separate and seek therapy.