First of all, welcome to YorkieTalk.
WELCOME TO YOU AND PETER!
Peter is still a very young pup. His whole world was turned upside down last week. Everything he knew changed. I would give your little darlin some time to adjust and socialize. He is trying to figure out the world around him. In time he will come around - I can almost guarantee that in a few weeks time little Peter will be struttin' his stuff, and loving you and your hubby like there is no tomorrow.
Would love to see pics of the little dude.
If you haven't already, it would be a good thing to take him to your vet to establish him as a patient.