Blocks going everywhere

Put the summary of the bug you're having here

What I expected to happen was...:
My Minecraft world to load in normally.

What actually happened was...:
Blocks in the world just loading in crazly everywhere. Looks like loading in multple worlds in one world continually. Blocks glitching everywhere. Edit: Now the colors are crazed out and going negative.

Steps to Reproduce:
1. Open Minecraft
2. Create World
3. When world loads blocks glitchout everywhere
3. ...