Should I not feel this way towards the guy im dating since I did something as well during that time? Please read need help/options ?

When I was 15 I went to sleep by my grandmothers and she was asking me to help her with her phone cause she had a porn site on there and wanted to save or delete a video from it, we were also watching a movie and at one point we started to touch and after some time watch a porn movie while masturbating. Afterwards I felt sick and spent the whole year wanting to die and feeling lost. She did some things to me when I was a kid growing up on and off. Due to that I never been sexual with anyone never even been on a date never had a kiss actually I did have a kiss and that was from my grandmother.. just typing this makes me feel sick! I’m 21 female and still a virgin I’ve had romantic serious penpals online, sext online, few older men stalk me in my hometown and through social media and I only have spoken to them online. I’ve always been shy and have anxiety and my past makes me sick! I have been dating a guy that’s amazing he gives me the world tries to work with me through my issues. But his past bothers me he’s had a threesome, sex on the beach while on vacation with a random, sex in a bar bathroom, etc. makes me feel insecure, jealous, worthless and wish I could have my fun but I don’t want to lose him this bothers me that I almost have walk away from him. He tells me he doesn’t even think about it he wishes he was a virgin when he talks with me, on his own he doesn’t wish to undo anything cause it doesn’t bother him but with me he wish to undo it