Im so sorry youre dealing with this. You need to do what's best for you and trying to "fix" someone who doesn't want your help only hurts you. This sounds just like my ex. If I would call him and he wouldn't answer I would get this gut feeling that he was at the bar and come to find out i was always right. It only gets worse with people like that. You need to assert what you want in a relationship, not be thankful he didn't cheat on you! Isn't that kind of a general rule of a relationship?

My ex used to tell me that if I was so upset when skimpy-dressed girls would flirt with him maybe I should dress and act like that too. He's not worth it! You deserve someone who won't hurt you like that. You did the right thing.