Sometimes, it helps to remember that (at least in the case of my STBXAH) that he just can't help himself. He has to act the way he does to keep his delusion going. He needs to insulate himself from the world, for some reason, and this is what happens. He has a disease. This is what I ought to expect from him.
My main source of anger right now is at myself. Letting that one go just seems to be that bit harder for me!