Obduction: At first it seems like my hope had come true! I could actually move while the graphics settings were set to high! Amazing, I always had to set almost all of them down to to lowest. But then the glitching started quite quickly. That tearing thing that goes diagonally down from left to right, which I don't know what's called.
I tried rebooting and turning the settings a bit down, and for a few seconds more it seemed fine, then the glitching started again. This is worse than before.