Hello, i have 18 years and i started to have impotency problems before 8 months, i visited a doctor and he told me that it is nothing its in my head. I know that this is not correct because he didnt make any test on me or smthing like that, before that i was thinking about sex more often and my erections were more often, but know, there are no erections almost at all, even when i am with my girlfriend. What could it be the reason of my problem? ( pls dont say its in your head, cause it makes me problems almost one year)