Past Rejection

I feel like I have one of the most perfect men God has ever placed on planet earth. I'm head over heels in love with him. He loves with such an intensity and sincerity. He thinks I'm the greatest thing since sliced bread. I could forgive him of anything. I know everyone brings some of there emotional baggage to a relationship. But my heart breaks for him. He was(is) a ADHD child. If you were one or/and have one then you know what that's like. He was told so often that he was annoying, stupid, irratating, amount to nothing.....the list goes on. He's been left and rejected by so many ladies in the past. Then a few mistakes that landed him in prison. After being insulted for so long I guess he started to believe it. Now inside he feels as though he can't possibly measure up. He has this fear that he's going to do something so terrible that I would leave him. I could never leave him. He has a great heart but can't see it. He believes he is somehow unworthy of being loved by me. All I can do is love him for the rest of his/my life. And keep doing what I've been doing. I can't think of anything else. How do I help him? What could I say or do to help him realize he's worth it? He's so worth it.