sex only when he wants it...

My husband and I have been married for a little under a year, but we have been together for 6 years. He used to initiate sex all the time, and be upset with me for rejecting him (not that I said no all the time). I love my husband. He's an amazing person. But in the last couple years, the sex has slowed way down because he hasn't initiated it as much as he used to. I have no problems with initiating sex, but I have a huge problem with initiating sex and being rejected. Even worse is when I initiate it, he tries to have sex with me, but then the sex is forced/awkward/or he can't perform. I get so frustrated and angry every time. Whenever he initiates sex, I get myself in the mood real quick. I'm not asking for sex super often. Maybe 1-2 times a week, especially when I'm ovulating (I tend to feel more frisky in fertile week). It just really seems unfair.