if you cannot see yourself with him...then leave....if it is just feeling sorry for him that is keeping you there then thats just going to be worse off...you are giving him signals through that that it might work...you need to sit down with him...stress that he is not a bad person...however due to the past events you need to leave for the sake of your sanity as well as his....tell him that if you stay together you will be continually in doubt and in fear and that is NOT how you imagined sharing your life with him forever....set yourself up in a place somewhere else....and if you still cannot make up your mind just suggest a temporary separation....just to be by yourself...collect your thoughts and go to a therapist to deal with the past....a leave and just go on dates with him once in awhile until you reestablish a connection ...however if you want to leave leave..which no one would blame you at all....then just be firm with him...as hard as it will be ....but you need to do what is best for you otherwise you both will be unhappy and stuck in a place where you dont want to be...what his parents do is their business....you cannot be the one to blame for their ignorance and mistakes....good luck ...