Aww poor guy. I think Chachi is right - it sounds like he hasn't had much contact with people. It's not always abuse that can cause this behavior.
First, try putting your palm up when approaching him. Putting your hand palm down looks threatening. Let him sniff your hand before touching him. Don't force your contact on him. He has to have time to learn to trust you. Try letting him come to you. Give him little bits of a treat when he comes to you on his own. Giving him treats will let him associate good things when he comes to you.
How's his potty habits? He might have an adjustment period here so please be patient. Never yell at him for doing it in the wrong place - you'll only cause more fear rather than wanting to please you (which is what you want).
Good Luck and Welcome to YT!
__________________  Connie |