Ladies, i need your advice

Two years ago today i was sexually assaulted by a man, ever since then i have finch when people put their hands on my legs or on my stomach or back. i can deal with it if i’m expecting it but not on my legs. i get flash backs, i shake uncontrollably and i start having a panic attack if they go too high; when i say too high i mean halfway up my thigh. i’m in a relationship and my girlfriend is so worried constantly. i’ve told her not to because if she gets too close to my limit then i’ll move her hand or i’ll move my body. i hate the idea of her doing things to me as well. we tried it once and i had nightmares for three weeks after it of me seeing the guys face in my wallpaper or i’ll look at a person briefly and i’ll have to look again because i see his face. i haven’t had that in over a year. i want to try fix it for her sake but i just can’t seem to do it. she’s not bothered by it but i really am because i know it kills her inside when i move her hand or when i start shaking because she’s gone up a bit far. i don’t have any idea of how to get over it, anyone got any advice?