He's too tired for sex!!!

Okay so my boyfriend and I moved in together shortly after becoming a couple. Before moving in, we had sex quite often. Now, we rarely have sex. I try to initiate, but he says he doesn't like having sex during the day, or he's too tired, or he needs to take a shower. . . it's always something. He knows it's upsetting me and making me frustrated that we go such long periods of time without hooking up, yet he makes no effort. It's gotten to the point that when we do FINALLY have sex, it feels almost awkward or forced. It's killing my self-confidence. Help?