I have PTSD and I am Very Jumpy

I have PTSD and am very jumpy. Every time I flinch people make fun of me or laugh. Even people who know what happened to me do this.. I’ve had people try to scare me on purpose. I’m 15, a grown man cowerker would hit the table with his fist to see me jump. I just really want someone to tell me they’re never going to hurt me, that i’m safe with them, offer a hug and say they love me. When I accidentally flinch away from them, but I fear thats never going to happen.