It seems like you have a number of options:
1. Live a letsrun.com life of quiet desperation.
2. Try banging some babes on the side.
3. See a marriage counselor together.
4. See a counselor (or priest, rabbi,etc.) by yourself.
5. File for divorce, as she is refusing to have sex with you.
Personally, #2, #3 and #4 seem like OK options, but it's your call. I do think that you have to be cautious of option #2, cuz she might be playing some games, as pointed out by someone else.
PS - I am not a doctor!