How do you not suck at this game

Title really. I've got 170+ hours in this game and I still feel carried, I can't clear auric damn most of the time, and regular damn is a bit of a toss up. I've maxxed all the classes so I think I have a good idea how to play the game but clearly something must be going wrong if I wipe most of the time...

I know about dodging, blocking, push attacks, dodge slide, but I still just get chunked by hordes and I can't manage hordes of elites when HISTG hits. I wanna be able to clear Grim Protocols when that comes out but tbh I might just pass if I can't consistently do aurics...

I play Psyker the most.