Nervous, advice, dating a significantly taller bottom and sexual tensions are about to break

So I'm 5'7 and the guy I've been dating for quite some time is 6'5 and I really really adore spending time with him and everything about him, I'm completely in love. We've been taking it slow but I know we're going to end up sleeping together very soon and I am overly nervous about being able to satisfy him with how much of a height difference there is and how positions are probably going to be restricted. I've never been with anyone taller than me and I'm typically a pretty confident person but I could really use some advice here from anyone else in a similar situation, am I simply over thinking things or it really significantly different?