Question HELP PLEASE! Sudden poor GPU performance

Oct 22, 2019
Hi so I was tweaking my nvidia control panel the other day and i just changed the V-sync to off and put the Power Management Mode into max performance and btw i tried OC'ing my monitors refresh rate from 60 to 75 and then i tried some of my games and it runs fine, i even got 80 fps ultra settings on most games (GTA 5, Far Cry 5, Witcher 3) But the next day, all of my games are performing poorly In witcher 3 i seem to be running it at 50-60 fps which is usually around 80 fps and the 60 fps doesn't feel like 60, it feels kinda 30 fps and it has a lot of stuttering, On GTA 5 it drops fps from 70 to 15 every second and the GPU load also drops to 15%. In my Far Cry 5 it just literally dropped the fps from 100 to a stable 30-40. Help me please this is a huge problem for me.
PC specs:
Gigabyte A320m s2h
Ryzen 3 2200g
Galax GTX 1060 6gb EXOC
2x4gb ddr4 2400mhz

Things i have done so far:
-Reinstalled the drivers using ddu
-Installed the game on my ssd and external still the same
-Reseated my GPU and cleaned it
-i reverted back to my 60hz
-Turning of fast boot
-Both power management option in windows and control panel are max performance