Whats going on in his head??!! Please help?

Sounds like he does. Also sounds like he's nervous. He's nervous about what you think about him, he's nervous that you're judging him, he's nervous that you might try to make a p at him and he won't know how to react in the right way. He's nervous because he cares what you think about him. He cares about you and he wants you to think he's just awesome as he sees you are. Understand? I suggest that you just keep going at it and wait for him to chill a little, let him relax around you. Once he gets to know you better, then I can almost promise that he'll stop freezing. You might be able to help him along by casually throwing out comments that you think he's great, etc. Just be yourself around him and hopefully he'll be comfortable enough around you to do the same.