Only horny when husband isn't around?

I thought I had a low sex drive until my husband left for WTI training for the marine corps. When he's away, all i can think about is sex, but as soon as he comes home for a day, my sex drive is gone. Sex is the last thing I want around him, I'd rather watch a movie or just cuddle. It can't be that I don't think he's attractive, obviously I do because he's who I think about when I'm horny. I feel bad because it's affecting our relationship when I turn down sex and it's frustrating for me when I want it so bad, and then he's here and I don't want sex at all...has anyone else experienced this? Other than that, we have a healthy relationship.