Severe FPS Drops (5-10 FPS) in every game mode, even in Menus

when i start the game everything is perfect like my fps is around 100-200, i can search the menus, market, sbc's etc. but like 2-3 mins after i start the game fps suddenly drops to 13-14-15. i tried everything, i know my pc is so good i dont want to write all my pc information, believe me its good and i know this is not about my pc. i tried to play rivals, everything was fine until the starting of the match. when the squads show off the problem occurs again. fps drops around 13-14 again. when will you fix this s*it?