Drastic performance decrease in the last 24 hours - completely unplayable - all skills invisible

The game has become absolutely unplayable for me today. It looks like something from 1996 all of a sudden. As if the upscale option is set to the lowest (it is not). Loading into town take 5+ minutes and I can hear my character for 3 minutes before the loading screen disappears. All projectiles are invisible. It has a 50% chance to crash if I press any button. I am on DX12 (like always). I tried changing to Vulkan and DX11 and it got worse and it took me 30 minutes to successfully change back to DX12. My computer is having no issue whatsover with any other software or games. I've never a seen a video game behave so poorly before. It appears as if the game refuses to use my CPU as it is not utalizing it AT ALL when I check task manager, whereas it would normally be using a lot of resources. I cannot overstate just how bad the performacce is, most animations no longer exist for me, for instance.

Bug Report ID: #3035946817

Edit: yesterday I had 200+ FPS and the game looked normal. Today I have 30 FPS and it looks like something that was released 25 years ago.