mamasmitty -I think I relate to what you are posting. I too felt guilty for hurting my AH. That is one of the main reason's for staying with him so long. He lost his mom, his brother and I didn't want him to lose me. I'm finally realizing that what is happening to our marriage is b/c of nothing I did. I did everything I could to make things work with him and us. He actually had me convinced that I was the one who had the problem (well, he was somewhat correct on that theory).
The Sex thing - totally relate. I think that is because it was expected of me whether I wanted to or not.
I also agree that as time went on the problem got gradually worse. But that was because I was tired of being his doormat.