Bonbon,
I've felt just like you're feeling. Don't be hard on yourself. You are dealing with a lot! That awful need inside creates so much pain. Dealing with another woman and pregnancy is very difficult. Living with an A and raising a child!
You're handling so much right now. I don't think you realize it. Your anger is understandable. I think a restraining order against this other woman would be in order if your husband would go for that.
I also think you should go find support for yourself. I don't know if you go to meetings or counseling, but I think it would help a lot if you found support. I just went to counseling just for support while I went through a difficult time. When everything got sorted out I quit going. It made things much easier to deal with just talking to someone else and them telling me I wasn't crazy for feeling the way I did.
I'm sorry you are going through so much. It won't last forever. This too shall pass.
Hugs,
MG