my boyfriend doesn't turn me on??

Me and my boyfriend have been together for 3 years, sexually active for 2. Just these past few weeks every time he's tried to have sex with me I always say no because I'm not in the mood. We tried yesterday and he fingered me and stuff and usually I'd get wet but I wasn't wet at all, even after sex? I'm kind of embarrassed by it, sometimes in my alone time I'll get horny but never with him anymore. Does anyone know what would cause this? I've been kind of depressed lately. So I don't know if that has anything to do with it.. I just feel so bad.