I know that when everybody says 'don't engage' you kinda understand, but not really 'feel it'. Because I was the same.
Your husband needs to play out the drama. He desperately needs you as part of it. If you deny him this and cut all contact, he will be wondering what you are thinking, whether he has a chance, what people think of him, etc. With any actual feedback from you, he can then engage you and air his (screwed up) opinions and justify himself. If you swear at him, he will think it was a good thing that he left you and add it to his 'list of your faults'. If you are nice to him, he will feel validated, and come up with even more crap. The best revenge really is not talking to him at all, or just say 'I am sorry you disappointed me like this. I hope you are happy.' Do not give him any satisfaction. He sounds like he cares about what you and other people think. Only by not giving him any access do you make him go through all sorts of worst-case scenarios.
I once made the mistake of engaging with a loser who cheated on me. I screamed at him, found the girl's number and spewed out ugly things, etc. This proved to him that he was right to leave me (since I am such a bitch), and OW consoled him, saying oh you poor baby you suffered so much staying with that horrible woman, whatever.
I had a friend who tried to stop me at that time. She found out her boyfriend was cheating on her, and she simply disappeared. He was dying to find out what happened. When he begged to see her, trying to find out what happened (and how much she knows), she said he disappointed her, the relationship ran its course, and that she hopes he is happy in the future.
Well, a year later, my ex was happily posting pictures with his new girlfriend. My friend's ex was, after three years was still begging her to take him back (she never talked to him again), telling her she's the only one he ever loved.
Your husband needs to know how you are feeling, what you are thinking. You already gave him an indication. Don't give him anymore. Don't listen to him. Don't talk to him. Let him stew. I know it is hard. But it really is the best revenge. Please try.