Pc games suddenly jerky?

I wanted to start my wallpaper engie normally and it stuttered like the live wallpapers. Then I started Battlefront was the same and then I wanted to start Fortnite and since 1Fps in settings they are limited to 144.

Before, everything always went well.

Year each. An idea what could be?

Hardware: GTX 1660super, Ryzen 5 3600, Asus Prime b450 plus

Your SSD or HDD may be full

I have enough memory