Are you on an antidepressant? Some are famous, especially SSRIs, for tamping down the sex drive. Might be worth a try.

If you are already on one, maybe talk to your pdoc about switching to one more well known for knocking your sex drive out.

On the flip side, are you on any drugs that will increase your sex drive? Buspar and tegretol both did this for me. However, I simply masturbated more.