Big big big hugs to you, first of all. I haven't been where you are, but from friends who have, I have heard exactly what you're saying: The images flashing before your eyes, the incredible sense of betrayal, and a need to know exactly what happened.
I don't know how you get over it. I know that you can never know that it won't happen again -- that it will have to be a leap of faith. And that only you can know if you have that faith and the willingness to work on it.
I know you know this, but I'm going to say it anyway: You know that none of this has anything to do with you, right?