Pits were literally bred to be aggressive and are innately so. No one questions the purpose of a Labrador retriever or a greyhound. People aren’t abusing pit bulls to turn them mean, not by a long shot. They’ll easily turn on loving owners for no reason at all.
This honestly sounds like what I’ve been experiencing for months and my Dr can’t figure it out, the leading guess right now is long covid. I noticed on the Wikipedia page it even mentions long covid, are they similar? Does your lymph node randomly swell up?