I read somewhere that the less you have sex or be intimate with your partner, the less you want it. (Kind of like eating, the hormones/chemicals that tell you to eat only get activated when you eat, so if you don't eat, you can easily forget to eat). Perhaps this has happened with your girlfriend (and maybe you too, Sugahorse?)? I think you should probably try to talk to her about everything and see if she is willing to work on getting you both to a place where both of your needs are being met.

Good luck!