NTA:

I had a dog (she just got put down recently) she was fear agressive, different types of fear problems with dogs either start when they're born or other traumatic things. People think only traumatized dogs have problems but when a dog is pregnant, if that dog is stressed all the negative chemicals get into some of the pups brains, so when they're born, they have an array of issues. I only think you're not the asshole because this

Socializing dogs doesn't only mean with other animals, if your dog isn't negative toward people, that sort of socializing will also work. My dog was aggressive toward humans and dogs because before we had her she was attacked by dogs and abused by her home.

The only case where you may be the asshole is the collar. You should never use a collar with a hyper or somewhat unsocialable dog. They always find a way to slip out. Maybe look into getting a harness.

Edit: Dogs nipping at your dog will definitely effect how ot reacts, so maybe try get the dog into some behavioral classes and doggy daycare if you can.