Well the best thing to do is ask yourself why? Is there something that happened to you in the past, was it your upbringing to not talk about sex, or are you afraid of something? Most of it sounds like embarrassment and the only way to overcome that is too either "do it" or talk about it.
A lot of help I know. I went to therapy to overcome my issues with sex and it was the best thing I could have done. I love my hubby but I was just to scared and it felt dirty. But my therapist helped me get to the bottom of it and well I feel better. I am still shy when it comes to saying things out loud.
One suggestion that has worked for me is talking about sex when we arent having sex. It takes the pressure of the performance. We talk about sex at different times like when we are laying down or even over dinner. I also bought a sex book and we both got to point out different things we really liked and didnt like, without saying a word.
Just explore different things, its very hard at first but as you get going you will become more confident and that I have learned is a total turn on for a guy.
Good Luck