What you are feeling are the normal feelings of a human being. Have you read "After the Affair." It is helpful in that it will tell you things you are feeling and how your spouse feels. Your defense mechanisms are shielding you and helping you to deal with the situation.
I'm divorced and I still feel things when I am around my W. She has included me in her life (to a point) and in family life with the kids. She has gone to church with the biys and me as a family. It's difficult, but I know that I have to be prepared for whatever life throws my way.