FPS problem

Hello everyone i really need help for this problem i play league with 140 fps sometimes more or less. last days i have weird drops from fps from 140 to 3 for 3 sec or 4 then go back to normal with a ping change from 90 to 1000, not internet cuz my screen freezes. i tried everything in youtube didn't work its made it worse now i keep getting drops every 5 s over and over again, I can't play can't even farm or do anything it's so bad to play like this so if anyone knows how to fix this PLZ tell me

i tried to clear files. tried to lower everything from very high to very low. tried to update everything in my pc. it's not the GPU or CPU getting hot i have a cooler under there.

cuz it's happened those days it's can't be my pc it's something happen to the game cuz it's unplayable

i hope someone helped me Thanks