The most successful so far is an anti-depressant. Duloxetine. SNRI. I do have some of the side effects - my libido is markedly decreased, but it was fairly high to begin with, so I'm probably at about low-average now. I can still get in the mood on demand, and still want to initiate several times a week, so I'm more than happy to make the trade off to not have a basically constant headache 80% of my waking hours.
Off label prescription is a pretty common thing. Personally, I'm glad for it.