Looking at the requirements of the games your shouldn't be having such low FPS. Perhaps your GPU is failing? or you had a faulty one. Im not sure exactly what the problem is if you have your Nvidia drivers updated and direct X up to date. Sometimes FPS fluctuate, if the card is failing or you have low memory or power, but im pretty sure your power supply is fine and your memory is enough. How long have you had your video card?
Like a 6 days bro