Question pc doesn't run as good as it's used to after it runs for a certain amount of time

[AntoBazaTHA26]

So when i start my pc all the games run smoothly but after a while my fps starts to drop and i need to restart my pc in order to get good frame rates
any ideas?

 

[rgd1101]

full system spec? include make and model of the psu
cpu/gpu temp and usage?
ram/hdd/sdd usage?

 

[AntoBazaTHA26]

full system spec? include make and model of the psu
cpu/gpu temp and usage?
ram/hdd/sdd usage?

i5 9400f
8x2 corsair vengeance 3000mhz
b365 pro4
gt 730 2gb
season s12 620w

https://imgur.com/a/dFTIfnp

View: https://imgur.com/a/dFTIfnp

first pic is my idle usage and the second one is when i open the game
gpu goes as high as 87 in some moments and the cpu doesnt go beyond 45

Edit:
btw when i fresh restart the pc my usages are even lower or the same and the games runs way smoothly and dobules the fps