First, breathe and know that it'll get better. If you're having sexual intercourse with anyone random, stop doing that. It'll only make things worse for you. If you're having sexual intercourse with your partner, let them know how you feel and see if there's something that they could do to help you move past those feelings. I used to get flashbacks in the middle of having sex and I would freak out. I'm now married and thanks to my hubby, I'm not having flashbacks during sex and I rarely feel guilty or dirty anymore. We actually started out cuddling with our clothes on until I was ok with that and it progressed to us having a 13 month old daughter and a son on the way. I still have a problem at times with just being shirtless in bed if he's not in the room with me, but that's more due to the fact that he makes me feel safe.