thanks everyone!
I forgot to say that in addition to not playing the sex 'movie' in my head over and over again I also stopped shaking and the chest pains are less frequent. I still can't eat or drink normally, it's like I have no tastebuds anymore. I lost 6 pounds since I found out.
And to be honest, I don't think I will ever forgive him fully, and I most certainly will not forget (I'm not the forgetting type), I just want to give him a second chance, just like I hope he'd give me. I mean, this is the first time in our 7 year relationship that he's effed up big.