So, while playing Minecraft yesterday, my laptop crashed twice. After the second time, I went to play Minecraft again and it was laggy and it would take many minutes for chucks of the world to load. I brought up the debug screen and saw the "P:" in the top right corner and the Used memory % fluctuating. It would go increase from 30% to 50% and then go back down to 30% and repeating that. This happens on my current worlds and even if I start a new one. Any idea what the problem could be? I reinstalled Minecraft and Java and it's still acting up. Any help is appreciated.
I screnncapped the problem to see if that would help: http://gyazo.com/cb88fd5f61f3c1f9e4abd94abac71a97 (view in mp4 format)
Allocating more memory is easily done in the new launcher, If you need help just ask. ;D