Being on top

I'm naturally submissive in bed. And so when I am asked to get on top I have the most difficult time ever. I don't have an orgasm when I'm on top because I'm so focused on doing it right. I have a hard time staying balanced. And it's difficult for me to get it "into position", you know? Does anyone else have issues like this? Any advice would be greatly appreciated. I'm seeing this guy that is a little older than I am and things are starting to heat up. I don't wanna embarrass myself.