Possible sexual repression?

I don’t know if that’s the best way to describe it, but I feel like my sexuality is repressed in some way.

First of all, I am unable to express my sexuality around other people. The only form of sexuality I feel comfortable with is masturbating in secret.

I feel uncomfortable when it comes to sex. I can’t even talk about sexual topics with my friends (who are the opposite of me as they have regular gangbangs with stangers).

I finally managed to lose my virginity in my very late 20s but I always feel bad after sex, I don’t know why.

Actually I might know why. Growing up, sex wasn’t just a taboo, it was evil. My parents always made it very clear that sex is bad, and made sure to shame me if I showed any interest in such things. One day I kissed a girl during a game of truth or dare. My mom publicly called the girl a slut and made sure I never talked to her again. Also I was super sheltered in general, which didn’t help.

So I feel like I interiorized these beliefs that sex is shameful and that I still uncounsiously believe that, which makes it impossible for me to pursue sexual relations, even though that’s also what I want, in a paradoxical way.

What should I do?