Keyboard/game lags at 6-10 minutes everygame

This has been and issue for me since 9.6, every game at 6 minutes my fps drops to 20, my abilities are delayed like 10 seconds plus my ping jumps to 200 even though i have ethernet,this has made the game unplayable for those 4 crucial minutes

I reinstalled windows,reainstalled the game,works perfectly fine in a custom game