Unfortunately, we can't un-know what we know. What we can do is look at the person and ask ourselves if they are the same person they were when they hurt you. Have they learned their lesson? Have they shown they are sorry? It's very hard when people say, "Don't bring up the past" because, for some, this a license to excuse repeated bad behaviour, but if he's been a good man since, try to talk your feelings over with him. It's perfectly understandable that you would need some reassurance. All the best.