So earlier this week I had a second date with a girl and to my surprise, was able to escalate all the way to sex. Problem is, I had a ton of adrenaline pumping in my system and I just could not get hard. She was understanding, I made her cum by foreplay anyway and then later I was able to actually fuck.

Problem is, the anxiety is still there and I just need to convince myself that there's no problem. It's a vicious cycle where the more you think about it, the worse it gets. How can I get past this?

By the way, I'm a fit male aged 20, and I'm still getting morning wood so I know the problem is psychological.