End a relationship when not sexually satisfied

Me and this woman "Katie" have been together many years. Last year we had a bit of a rough patch when she cheated and lied behind my back only to have to find out myself. After sometime we decided to stay friends and became roommates while trying to raise our son. After sometime I began developing something for a co-worker and when my ex found out she become very jealous and wanted me back. After much talking and working out our issues we had in the past we decided to give it another go. After some months went by we seemed to fall into some of the same problems. One of the big issues I feel we have is sexually she is really all over the place. If I wanted to have sex with her I don't see her saying no, but at the same time I would like to be lusted after and have her come on to me wanting her the way I want her all the time. I've told her how I feel and she says she understands but then doesn't fallow thought and it makes me feel like I'm not attractive to her and as if the things I tell her Id like done to me and my sexually fantasies and desires don't matter. And I do things that she likes/wants but seems to be a one way street. Am I wrong for feeling like I've reached the end of my rope on this issue and its not getting any better.