Huge drop in FPS GTX 770

[Hashbash]

I am running on an i5 4670k OC'd at 4.4 GHz (running at low temp), 8gb of RAM, and a GTX 770 (graphics setting of game are optimized by GeForce experience). I haven't had problems and have been playing this game on and off for years. Coming home on break I noticed that sometimes FPS will drop and even the sound will stutter. I tried lowering the graphics settings but it didn't improve performance much. The problem is starting to get worse, any ideas?
[video="https://www.youtube.com/v=kkL1shNdjE4&feature=youtu.be"][/video]
[video="https://www.youtube.com/v=DhAls_hg1p4&feature=youtu.be"][/video]

 

[sizzling]

What's your CPU & GPU temperature when this happens?

 

[TCobra]

GPU Temp? And what programs are you running in the background?

 

[Hashbash]

What's your CPU & GPU temperature when this happens?

The CPU temps stay around 45C and maxed out at 52C. The GPU sits around 52C and maxed out at 62C. I attached another clip that shows the gameplay while I was getting the temps.