she may not have that great of a libido. its kind of like how guys try there hardest to be nice and sweet in the beginning, and after six months we get tired of "going out of our way". it's probably the same with her. she wanted to make you happy, and most woman think that sex is happiness to men. after a while it got tiresome and her true colors are coming out. what they dont realize is that men will view the decline in sex as rejection, just as women view our decline in sincerety the same. ive had relationships where after 2 years the only thing that was going right was sex, and we both definately had healthy libidos. im in a relationship now and sex is the major problem. are libidos simply arent in line. try and go a month without initiating sex, if she doesn't come to you, time to move on