Having Some Stage Fright. Any Advice?

I never had a problem in the "on top" position before my current SO but for some reason with him I get terrible stage fright and can't get into it. We've been together for roughly 2 months and have known each other for years. He is extremely sexy and I want nothing more than to show him a good time. And I'm not inexperienced when it comes to sex. Maybe I just really want to impress him? Seems counter intuitive if that's the case, because in order to impress him I'd have to actually show him that I know what I'm doing... What the hell is wrong with me?! Lol. Is there anyone else that has experienced this with someone that has some tips on how to get over it?