Performance Anxiety

So recently I started talking to this girl, and when the topic of having sex came up I was excited (who wouldn't be), but when the time time, I was extremely nervous and couldn't get it up. My leg bounced uncontrollably like when it does when I get very anxious, and I simply just couldn't get hard. Whatever though I was more embarrassed than mad, and still ate her out and fingered her into orgasm so it wasn't for nothing. It also sucks cause I can get hard thinking about it. Wonder if there's any tips or tricks to calm your nerves before sex for anyone else that experienced this.