I'm NEVER horny

Please help. I'm about to turn 21 in less than two weeks. I have been with my current boyfriend for over 7 months now and I am NEVER horny. Never is not an exaggeration. I talk to all my friends and they tell me how much they want to have sex with their significant others ALL the time, but I never want to have sex with mine or anyone else. Sex is the last thing on my mind. I need help, I want to be horny.