Question Games are getting very laggy

Jan 5, 2021

Lately i have been having problems on my pc while playing games. my game is getting very laggy (20FPS when playing Valorant) and i don't know why, when i check in the task manager, it shows that my gpu is only using 10-20% while my cpu is only using about 20% when playing Valorant ... is that ok? When I play games, my PC doesn't overheat and the temperature is in 45-50° C (113-122° F).

I've deleted some files that could possibly be malware with malwarebytes, I've cleaned my PC both physically and the files inside the PC, I've tried to lower the quality of my video games but still the problem doesn't go away. This problem started yesterday when my PC crashed suddenly, before that day... my PC could run anything smoothly.

PC Spec :

Mobo : VenomRX H61
Processor : Intel Core i5 3470
RAM : HyperX 4GBx2
Graphics Card : AMD RX 570
PSU : AeroCool LUX 550W