My husband doens't want to have sex with me?? Help!?

Lately my husband hardly have sex, we used to have sex a few times a week, now its been down to about twice a month.. If i want it, i can literally throw myself at him, get naked right in front of him, and he won't do a thing. I try to unzip his pants and go down on him and he pushes me away and says he's not in the mood or maybe tomorrow, but it never happens.. I am an attractive girl, young and fit.. I've tried lingerie but he see's it as a waste of money. I've tried toys, he doesnt care for them. The only time we have sex is when he comes on to me about once a month, even if i'm not in the mood i still give it to him because its my only chance to satisfy my needs and i dont think its fair. and i've explained this to him. Someone please help give me some ideas, i dont know what to do..