I spent a little time reading your sitch. Not all the way back, but quite a bit. Im with Gerda on this one. You sound like a kind and loving person. That is a good thing. If you want to be kind to H, do it for yourself...not for him. I think that is how you can still do it without expectations from him. I mean dont be a doormat and try not to over analyze everything he does, but you can be yourself without worrying how he is going to take it.
My W had an EA early on and it didnt last long. Not sure it sat well with her. That was over a year ago and now she is moving out. I am fairly certain there is no OP, so I get your confusion over it. I am with mine to. I almost feel like it would make more sense and help me get over it as I dont think I would hold on so tight if she was leaving me for someone else. But why would she leave just to leave? Am I that unbearable? The answer to that (which is hard for me to wrap my head around) is that it really has nothing to do with me, and I dont think it has anything to do with you either. Its about them. I think they are looking for their independence...to FIND themselves. That doesnt make it that much easier, but its easier to understand than it being something that I have done. I know Im a catch and I bet you are too. They MUST be broken to not see that in us.