Virgin, having a hard time with sex

My bf and I have been dating now since July. I care about him very much, always enjoy his company find and am totally attracted to him. We have tried to hit some "bases", I know what he enjoys but we've yet to find anything that I enjoy. I love being with him but I can't seem to feel sexual pleasure. I feel really guilty about it. He makes me feel really comfortable and assures me that there's no rush and we'll figure it out. For one it's always in his car and well maneuvering gets difficult LOL. Secondly as I am a virgin and have had a lot of body insecurities I think part of it might be psychological. He is also my first BF. When I try things out myself nothing seems to work either. 
I was wondering if anyone else has gone through this and had any advice? Thank you