Intimacy Struggles

Ok so, first of all, I’m 17, and I had a relationship with a guy from 8th grade to sophomore year. He was terrible, never took me on a date, coerced me into doing sexual things for him, and made me feel bad for wanting him to treat me like a human. Basically he treated me as a friend with benefits. He broke up with me and then about 4 months later I started dating my now boyfriend. He is awesome and is everything I ever wanted, and for important information we are long distance. Anyways, so starting in about October (we started dating at the end of August) I started feeling this weird feeling and it happens when I do intimate things with him. He is super understanding so we take things very slow, but many times when I kiss him or when things get a bit more heavy I panic and need to stop. And then we stop and just hang out or talk about it. I want to do intimate and sexual things but my body just freaks out. I don’t know why, and it sucks. I am seeing a therapist for it, but it’s so hard. My boyfriend wants to show me him shirtless and I really want to see but he doesn’t wanna show me the first time in person because he is very insecure so he wants to show me in picture first if I’m ok with it. I really want to see but I am a bit scared and panicky and I’m scared that I’ll get the feeling when I see. What do I do, I feel ready to see but I don’t know. I feel like I just need to rip the bandaid off lol I need advice