My experience is just like yours. It happened this summer. The first attempt I messed it (i think I can't use the expression "I fucked it up" because that's just what didn't happen). I couldn't get a strong enough erection.
The second attempt and my first time (
) it went perfectly. I was nervous because of the thing that happened the first time. But after a few minutes of foreplay (yeah, I too like to do the stuff girls like) I really was into it. If you really are enjoying, you won't even remeber it's your first time. You will be enjoying so much that you will not want it to finish. In my case I lasted quite a long (the trick is, enjoy, don't think of cumming, people tend to overprice the orgasm and think of it as the objective of sex... just enjoy the ride). Remember, it is not an exam, you don't need to follow a requirement, just enjoy, taste the moment. Don't think it's your first time, that's part of your past (or what has never happened in your past) and it stays out of the bedroom (car, beach, or wherever you do it).
Good luck!
(By the way, the following times I have done it, my trick of just enjoying still works)