You need to stop this "play." It isn't play.. it is domineering your puppy. Advocate for your puppy. He needs you to prevent this. He does not need "dog friends." He needs YOU to be his primary bond.
Remember, your puppy is a little kid and he is also a little dog. Allowing this play, which is NOT play could physically and mentally hurt your puppy. It is like taking a 3 year old out and letting him play with rough 15 year old boys who will knock him down and pin him or even toss him back and forth. You would not allow that to happen with your child! Don't allow it to happen to your puppy.
Remember, your puppy is a little kid and he is also a little dog. Allowing this play, which is NOT play could physically and mentally hurt your puppy. It is like taking a 3 year old out and letting him play with rough 15 year old boys who will knock him down and pin him or even toss him back and forth. You would not allow that to happen with your child! Don't allow it to happen to your puppy.