Okay, starting with the TLDR. Guy at work is being a real POS to me but as far as I can tell it isn't founded in any sort of racism or sexism and therefore isn't covered by the EEOC, so I'm wondering what to do and where to go about it.

The Long Version:
I was hired a few months back by a common pizza chain as a delivery driver. One of the other drivers had been working some pretty serious overtime because they had a hiring shortage, so they were pretty eager to get me going. However, said Other Driver wasn't happy about this. He started yelling at me for petty slights, anything from leaving a spot on a dish(somewhat understandable) to looking at his tickets(This is a thing that all drivers have to do, as the machine doesn't sort the tickets printed, only prints our employee ID on them, so we have to kinda hunt for our own in the pile) to simply existing in his presence(he got mad that he had to look at me for some reason).
The harassment obviously got reported to management and later HR, as I was being explicitly prevented from doing my job, but that was nearly a month ago and multiple times this other driver has been spoken to about this, and every time he comes down harder on me for reporting him. The berating has now turned to threats, everything from the vague "I warned you being in the store, and now you won't like what happens" to the specific "if you look at my tickets again I will call the police and you will be sent to jail." I'm not exactly fearing for my safety here, but it does stress me the hell out to be in that space.
From everything I looked at, in order to have a hostile work environment claim with the EEOC, it needs to be founded in some sort of discrimination based on race, religion, etc. That isn't really the case here. So my question then, is where do I go to report this, and how?