This is something I struggle with. Mostly, the only people aggressive towards me are middle aged, white males that I barely know.
Just the other day, I was talking in a group of people, and a man in the group spontaneously said, "I want to punch you in the face right now." My fiancé was sitting right there, but he didn't seem to hear. So there was this awkward silence and I was apparently properly shut up (I was mentioning a tv show is all) and the conversation carried on.
It really bothered me and I didn't know what to say. No one seemed to care.
This happens sort of frequently - I had a stranger in a park yell obsenties at me for no reason. He may have had mental issues. I had a drunk man at a wedding try to sexually assault me in front of a group of people, but at least someone stepped in to help that time.
I just don't know how a I am supposed to react to stuff like this. It feels awful.