Have you talked to your doctor about it? You don't say how old you are or if other things are going on with your partner, etc. but to have NO sex drive at all sounds unusual.
Go to your doctor. If you are not comfortable talking to your GP about it, go online and check out some doctors who specialize in 'female' issues. You can find reviews and recommendations, etc. that will help you find a doctor you think you would feel comfortable with who is part of your insurance group.
Go see that doc for a pap smear, breast exam, - all the female stuff, and TALK to her about what's not 'going on'! I think this just happens to some women, but there are all sorts of reasons, both emotional and physical. Either way, I am SURE there is something that can be done to get your body interested again! Good luck, and don't worry- see a good doctor and I bet you will feel more like your old self again soon! :)