Look, you have two kids. There must be some communication if there is going to be co-parenting. You could set up an intermediary that could pass information back and forth between you to if communication with him is just too painful for you. This person would strip out all the emotional garbage and just pass on the facts dealing with the kids.
I ask about the NC because I don't know what you are getting from it. Most people do it to protect themselves for either their spouse's anger, from an active addiction, or from the details of an active affair.
And I don't believe for one minute that your H isn't having an A. He seems to need validation from women to prove his own self-worth. If he isn't getting it from you he is probably getting it from someone else. I've seen tons of these situations and I can only recall a few that didn't involve an affair. And if his is having one it explains so much of his behavior.
I'm a man . . . But I can change . . . If I have to . . . I guess . . .