I think many men experience this. They are afraid that they won't perform well enough and actually become of afraid of having sex at all. The media often makes us believe that most guys out there are, so to speak, "ready, willing, and able." Women also suffer from this fear.

I think that you are a very sensitive man and that if you focus on your emotions you will do better to be more comfortable, but I know that's not easy. Maybe the personalities of some women may be intimidating, also.

For me, someone who is very head-strong, stubborn, or who has a strong personality often terrifies me. I try to go with people, men and women, who are softer and sweet, if ya know what I mean. That may help you, also.

I hope this helps some.