Perhaps she is taking out her anger, frustration, and pain on you because she knows you love her and will take the abuse? I do that to my husband sometimes. Not because I want to hurt him, but there's so much poison inside and it has to get out. Most of the time I don't even realize I'm doing it until later - after the damage has been done.

She may also be pushing you away because she feels you deserve a woman who can have children with you. This is a very difficult issue for some women to deal with. It makes them feel as if they are less of a woman, some how to blame or some how deficient. I really think some therapy would help her deal with this problem.