i HIGHLY doubt this would be the problem, but i had a second monitor plugged into my laptop and used it for random stuff while i was playing games. the problem occurred after i got rid of the second monitor
what are the chances that would be the problem? lol
I know this is a shot in the dark, but what antivirus are you using? For awhile, I had Norton - I know, don't yell at me, it's gone now - and it liked to make sure the system ran how it wanted to run. Randomly fps and performance would drop to the same lows you are getting and it would clear up after a day or so. The last time it happened it persisted for a week and I uninstalled Norton. I instantly got my performance back. Otherwise, make sure nothing else is running in the background, especially any programs that are updating without you knowing it. That's all I have to say.