FPS drops? - 5

I have a huge problem. All my games run around 50% worse than they should. My components: rx 5700xt, i5 9600k, 16gb ram, asus rog gaming b-360. For example, I have strong stutters in Fortnite and only around 80fps even though I should have 230 according to the benchmark. Also in csgo I only manage 200fps (benchmark 440fps) which is really a joke for the money I paid. Please help me, I'm really desperate. BIOS and drivers are all up to date. Should I maybe reset or rebuild my PC one day.

Please check if you have updated all the drivers and also check if there's a new Windows update for your PC.

Yes, if the driver has seen the software, then I have it up to date