I would sit down and ask him. I tend to think that when people get hurt in past relationships, as you have been, it is a natural defense to clam up and worry about "scaring" a possible good man (or woman) away.
You deserve happiness, and I am sure this guy is just a really great guy, otherwise your natural instincts (which are also shaped by your past experiences) would kick in, and you would automatically run from him. Just talk to him, and enjoy your new found "love." As stated before, you truly deserve it, so for God's sake, ENJOY it!
Good Luck!