I think your therapist's insistence on talking about your sex life is bordering on misconduct. And asking you why you are not having sex, is over that line.

Implying that someone should be promiscuous is flat out WRONG. And there is nothing wrong with someone your age not having sex, and if you are having emotional issues it's a good idea to be cautious about sex, sex and emotions are so intertwined.

I don't know all the details beyond what you posted so this is just an bit of a guess, but it sounds a lot like he might be trying to manipulate you into having sex with him.

And if you "hate" him don't see him any longer, find a different therapist, and inform his supervisor about what he has been doing to you.