Dano,
I'm 24 now, and I have the same problems as you do. Did you doctor ever identify or suggest the "type" of hypogonadism that you have? My blood
test results show nothing that matches the traditional "primary" or "secondary" patterns.
My doctor made a smiliar suggestion to yours. He considers the low libido situation a "repressed libido." His solution is anti-depressants -- Wellbutrin, specifically. I'm the last person to tout AD's for ED, because I've been on 14 of them since the time I was 16 and now. However...
To be honest, the only time my libido absolutely surged was when I began taking Wellbutrin XL at 300mg per day. Of course, I can't be sure if that medication was the cause, because I also simultaneously quit HRT and used only Arimidex to keep estrogen low (under the belief that my problem was purely an estrogen excess and T supression, rather than just a mysterious ideopathic lack of testosterone.)
As for Viagra, I can't imagine how that would help. You need to be aroused the get the erection. As stated, we do not really have erectile dysfunction. Viagra is useful only when there are problems with bloodflow even though you are completely aroused. Don't get me wrong, though, I still have every ED drug legal in the U.S. (and Europe) just incase I need to be of service to a woman despite my lack of interest. It's just that I don't think that it'll fix/restore anything related to your problem.