I've seen this very thing with my H. If the children had any issues that could be remotely due to what he had done, H would shut right down. Guilt and avoidance I believe are at the core of this behavior.
Snodderly has given you very good advice. You are the primary parent with the children's best interests at heart. Keep your XH informed of the important things. Answer any questions and let it go with zero expectations.
I, too, was very resentful and angry at first that everything was dumped in my lap. Then, I started seeing it differently and it became a source of pride that I could and do handle everything as it comes.
After almost 3 years gone, H is telling me now that if I need any help concerning the children to please let him know. That's a 180 for him.
