I think the condom is the problem. As necissary as they are, they're horrible. I'd guess when you were with a girlfriend or alone, you are probably not using condoms?I'm definitely NOT a smoker! As I said, I have NO problem at all getting an erection with a girlfriend, or on my own, its just as soon as the door to the SP's place opens, it all goes south! haha!
I mean the obvious answer to getting/keeping hard is to use viagara or something.. pick up a prescription and just use it for hobbying, until you get the anxiety under control.