Sorry your bubble was popped; it always sucks, especially when you are not prepared. In the "gore community" there always were joking references to r/eyebleach for that...
As for actual resources? Mhh, not sure medical resources would even be suited for this.
Maybe you can view this as an opportunity to update your world view and take it as motivation to behave as to prevent society from sliding into dysfunctional equilibria that eventually make people do this.
For instance knowing that stress or poverty makes people violent or criminal and violence begets violence, you can make good arguments for prosocial policy decisions that may influence your voting behavior (at least this influences mine). Also there's a tiny amount of real monsters where nothing can be done, I guess.
And note that there is waaay worse out there, just describing it might get me banned here. But is seems to be who some of us are sometimes.
For that there is contextualising literature on criminology, but I have no specific recommendations on the quick.
Oh, and it might be a good idea to look for other Twitter frontends, that don't require you to use the official site. Maybe something RSS like if you want a feed of people you follow? A browser plugin? Dunno what's possible here, never used mainstream social media since the algorithmic feed era.
