I think, from what you've said, that it's more a mental thing for her. I don't think it's a physical type of thing. She feels she isn't fulfilling your fantasies, not giving back what you have given her.

This is more mental then a physical stimulation. I think you should focus on talking about it. Patience will be needed.

God knows I had to learn that I AM good enough for my boyfriend, and I AM fulfilling his pleasures. It took a while to see I was worthy.

If it pleasures her by doing what YOU like, then I think you are overreacting a little. If she is doing JUST because you want to, and is NOT enjoying it, then you aren't overreacting.

And that is my two cents. :)