You totally need to be medically assessed.

So many questions! First, it helps if there's someone loving or special in your life. But if there isn't, then have you tried masturbation? Sometimes trying to do something creates enough sparks to get a feeling you didn't think you had before. Were you having sexual enjoyment up until 10 years ago? Was there a particular incident that makes you feel this way that you recall? Did you lose a partner or loved one 10 years ago, and you're still mourning that loss? Do you feel unworthy of feeling pleasures? Do you still have regular periods? What does your doctor say about this problem, or have you told him/her? When was your last GYN check up? If it's been more than a year or so, then you need to be sure you're healthy by getting the basics checked out. Get a pap smear/pelvic exam/breast check/ and you'll probably be sent to get a mammogram. You know there's no way anyone on here can diagnose your problem, but my best guess is that it's a hormonal imbalance, perhaps due to periomenopause. That is, if you're in your 30's or older. Once your doctor has looked at the test results, blood / urine samples taken, then it's time to study why you feel undeserving of sexual love. It might mean you've convinced yourself you're not entitled to feeling pleasure - for whatever reason - and only you can resolve the issues, perhaps through therapy.

You're not alone and I can sincerely say the same, not for ten years but for a year now. The story as to how is its' own. A definition for us should be made if there isn't one. We are perfection at its' greatest and weakest, which makes it perfect, we are free.