First of all, do you know if she masturbates? If she’s getting sexual satisfaction, and if you know it, then that may alleviate your feelings of guilt that she’s getting no sexual satisfaction from the relationship. I understand that you want to please her, and sex is supposed to be a shared act, but obviously she has some issues with accepting pleasure from you, or I believe, any female partner. Her reaction is probably a result of some form of guilt for being a lesbian. She should go for therapy. If she refuses, then you’ll have to decide whether or not you want to continue the relationship. It certainly does detract from it, and if she’s unwilling to even try to see if anything can be done, then that might be enough for you to end the relationship. But hopefully she will agree to see if she can be helped, in which case you should be as supportive as possible.