Mine was a sort of one night stand but I knew the guy, weird thing was he was in my registration class when I was 11 and I only saw him 6 years later. I saw him twice at a club I used to go to (both times we kissed etc) before I took him back to (this is bad) my friends house. It was okay, a bit akward and not comfortable all the time, but okay. I enjoyed it to an extent. Anyway we started something, he was a child and I ended it.
In hindsight not the best decision of my life, very rash and not brilliant. I did feel embaressed for a while and really silly for doing it that way but what is done is done.
Sounds like the guy is being okay about the whole thing (not a complete kid like the guy I was seeing was), like he said he can't answer those questions only you really can.
If you had planned it to be special then I guess it can be a let down, but you shouldn't at all feel regret. In your mind you made a mistake, and maybe you did. What you can do is learn from it and if you feel like sex should be something special don't let it happen again until you really are sure and want it to happen.
Try not to let it get to you that much, you did nothing wrong! If it helps to talk about it, I know I talked about it a lot, just let it all out and speak about it with friends.
Edit: As for your friends taking the mickey well that's not on. Tell them you don't apprehciate it and they aren't at all being helpful.