I had a run-in with that recently, out of the blue. Scared me badly. Something happened at work, which seemed to resolve all right. Days and weeks later, though, there was a kind of residue that clung to the whole experience that that one event was snowballing into a generalized hatred for a growing number of a faceless "them" out there.
I talked it thru with a former dream therapist & realized a lot of it was being triggered by all the current political polarization. I'm being more affected by all the emotional currents around me that I think I'm ignoring, but I need the acknowledge what's out there--even the crazy stuff, if only to reject it. then my conscious mind will be concerned only with valid issues. Extremes ... such as irrational hatreds ... are less likely to be a problem.

We're overwhelmed, and we need to give ourselves a break, some quiet.