I read an interesting interview with a doctor who had had prostate probs and was on Viagra. He actually took one everyday regardless of whether a shag was on the cards, now that the cost has dropped its a viable policy for anyone. My own view is that you should aim for a shag as frequently as possible, but only one shag, those who are forcing themselves to have 2 or even 3 pops per session, are going down the wrong road, yes we all did that when we were young to show what studs we were, but its actually a waste of an orgasm. As for the op, find a girl you like and stick with her, you clearly don't have a reliable erection, and need a bond with the lady. There are lots of men like that, they just don't talk about it, with a loud voice in the pub.