If you were looking for answers to why your fps drops from 80 to 30 then from 30 to 10 don't worry you found the answer. And the answer is you can't do anything about it
#New Performance Bug (yippy)
gloomy karma
no one knows the reason why but until we do you just cant play the game for more than an hour or else you fps turns into a dumpster fire. Have fun in other games :D