I went a whole year being Single and having no sex.
It was hard! I have always had a really high sex drive and was always in long term relationships so had it on tap. Looking back the relationships were not healthy, bordering on abusive, but the passion and sex was incredible. My last relationship had a very bad break up with a traumatic sexual experience that turned violent. Hence the year of singledom, I've had councilling for this and have accepted it and it doesn't bother me any more.......or so I thought....
I have recently started dating a guy I've known for about 5 years, we were good friends, he is absolutely lovely, treats me so well, goes above and beyond really. I feel so comfortable with him, he makes me laugh, we have fun, he's caring, I get butterflies etc........ But here's the problem, we have had sex twice now, and I just feel so tense, and nervous and so flat
he's so attentive and into me and wants to please me, he's also very gentle and considerate.
It really is nothing to do with him, I want to do it and am attracted to him. I just seem to freeze and not know what to do. 
Has anyone experienced this?