I came looking through the forums for the exact same thing. The game is unplayable now.

Originally Posted by Bomor
I see. Does changing the game quality settings and/or lowering the screen resolution improve things? Lowering the screen resolution would only be a temporary test to see if your PC can handle the game better that way. Alternatively, enabling FSR in the game options may also help.

I am not OP, but I tried everything and nothing works. It is not limited to a specific save either, it affects all of them (retro)actively.