I agree with FMV here--neglect absolutely destroys a relationship. However, I do'nt think it justifies cheating, ever. But it is understandable to feel LONELY as hell when you feel someone is withdrawing for you or intentionally doing it (especially in those cases).
Soa, you sound like you do understand what you did. And I agree with Blue that in order to heal, you have to won what you did and find the root cause of it.
Yes, you did a very bad thing. It would be worse if you did not feel bad about what you did at all. You are not evil. I read something once that was along the lines of not punishing yourself constantly for misdeeds--that if you repeat the misdeed, then you haven't learned but if you do learn, then you have grown.
