Scared of sexual intercourse

I have a really big problem and i am ashamed to talk with my therapist about this. I can’t relax during sex, I always think that it will hurt. I tried everything to relieve this thoughts and stress but it is not helping, i just can’t enjoy sex.

I don’t know how to help myself. All the time i feel stressed even though i haven’t had that much experience. I am not sexually active for a long time but whenever i try to have sex with my partner is the same. I feel pressure that i am not good at it and also I started to feel anxiety after couple of unsuccessful tries. Now I don’t wanna even have sex because i think i am not good at it.