Can guys change dramatically from abusive and selfish to a trusting guy ?

Honestly, that mostly happens when the guy is trying to trick you in order to get something out of you. It's not every time, but there has to be a legitimate reason for this sudden change in personality, it just be, "I've changed," because that one is so easy to make up. If he was physically abusive, I highly recommend staying far, far away from him. Those types rarely change. If he was emotionally abusive, tread very lightly. But I think your best bet would be to move on with your life. If you have trust issues already, then it wouldn't be a good start for a healthy relationship. Good luck, I hope this helps.

I doubt it