I don't feel sexy anymore

I've been living with my boyfriend for over a year now and we've been having this problem that only I agree is a problem for about a year. We only have sex when he wants to. If he wants to and I'm not in the mood, he'll massage me and try to get me in the mood, touching me to arouse me until I agree. Whenever I so much as slightly come onto him, like kissing him for more than a few seconds, or if I'm so bold as to try and go straight for rubbing him, he ALWAYS pushes me away. He may come back a few minutes later having decided he does want it, but I literally feel incapable of seducing him. It feels like we only have sex when he feels an urge he needs to satisfy. That makes me feel like he sees me more as a means to satisfy himself rather than actually desiring me personally. Am I crazy? I am not exaggerating when I say it has been over a year since I got sex because I specifically wanted it. If we're both in the mood it's great, if he's in the mood and I'm not, we end up having sex. But if I'm trying to turn him on, I can't. I used to look at myself as an incredibly sexual woman but I don't feel that way anymore. And I don't know what to do.