I also dated another severely selfish woman. In that relationship it was much like the sibling poster mentions. There were high expectations of me, but even minor expectations of her resulted in her playing the victim or making lame nonsensical excuses. There was no reciprocity, zero respect, and no concern for the relationship as its own entity.
What both these women had in common was a desperation for approval and attention from others. This need was so large that I could not possibly fill it and I was ultimately made to feel that I was only a giver of attention and a tool to aid in the acquisition of more attention from strangers.
This type of thing is very obvious to me now, but when I met my ex-wife I was much younger and pretty clueless about women in general.