Okay it's been happening for a day now.
I get lag on every single server.
This lag isn't fps lag or ping lag.
I keep shacking back and forth as I walk and sometimes it knocks me backwards and jitters - that is the type of lag. (You know the lag you get when suddenly the server lags and everyone like freezes? it's like that but constantly)
I tried re-installing.
I tried speedtests and pingtests, they came back as normal.
I even got lag when just doing a local server by typing 'map midnight' in console.
It makes it impossible to play the game.
Any idea of how I can resolve this?