Last night me and a good friend decided to have sex. It was my first time so as you can imagine I was nervous.
After the usual foreplay we began. It was only a matter of minutes however and I lost the erection. I want to know if there's really any cause.. I'm turning 18 soon so it can't be an age thing (in the UK, 16 is the age of consent)
Now I'm left worrying that A. There's something wrong with me. B. That it'll just happen again, and C. That I'll not get over this and the worry will stop me actually succeeding.

Any real answers would be a help. My main concern is that it was more than just nerves, perhaps some real psychological or hormonal issue that I'll have to have seen to.