I've never had a girlfriend, and I am very introverted in general; so, thinking in the future, I feel incredibly embarrassed about the possibility of even having sex. That's not good, because the hypothetical is making me uncomfortable, and being as this is probably a defining experience in life, and I have no intention of being celibate, I am confused.

I'm not a very domineering or controlling person, nor am I the one to take charge, so sex seems to be very complicated for me. What do I do?