Based on your answers, I would say you do have a problem with your sex drive, and it is not just performance anxiety or an issue with this particular woman.
-Lack of sex drive.
-Taking propecia.
-Propecia causes lack of sex drive.
-Propecia is your problem.
It may not be so simple, but stopping the propecia is definitely a place to start.
I am losing some hair as well. I never even considered propecia, because my sex drive is too important to me. Losing hair sucks, but that’s life.
Horny Bastard