Originally Posted by Derbylicious
Perhaps you're just thinking about it too much now and you're becoming a self fulfilling prophecy.
Penises have a way of doing that!
I have a friend who can't get hard the first few times with any woman he feels a connection to.
If you don't already have an open dialogue about the issue you're experiencing with this woman, I'd suggest you start talking about it. Something simple. ("Hey, how about my dick last night? Wasn't working; I think you're too intimidating!") A little reassurance from her could do wonders for your brain. You won't be wondering what she's thinking, etc.
Also, how are you putting your condom on? Do you try to get it on as soon as possible when you know it's "go" time? That could be scaring your man parts. Try putting the condom on and not jumping straight to sex. Touch yourself or have her touch you with it on. Don't be afraid to go through a few condoms before you actually have sex.
But yeah. As others have said, stop thinking about it. Your cock will thank you!