Hi Joe and welcome to Yorkie Talk.
Hang in there and don't be discouraged, ok? Your boy is 2 years old right? And has always been the only pet? He is probably just used to being the only one in the house. My boy was 3 years old when I brought in my puppy, Mandie.
It will just take some time for him to get used to her. Most important thing to do right now is to give your boy a "safe place" where he can do what he is doing right now..get away from this new, excitable puppy. And after that, make sure you don't change how you treat him. Do everything for him first...feed, pet, etc.
Most likely, with time (give it a few weeks), he will come around. It's just new to him. There are cases where the pups just don't become "best buddies" but that is ok. It might not be what you had planned but as long as they can live in the same house, it is fine. I'm guessing that in a week or so, things will be different around your house. Patience, time, and don't change how your boy has always been treated. Hang in there.
Edit: Also, if your boy is not neutered, you need to go ahead and get that done soon so no accidents happen, ok?
