when i play the world loads super slowly , it crashes, lags, and screen glitches.(blocks vanish,turns different colors!)

Put the summary of the bug you're having here:block turning color and vanishing and crashing and .

What I expected to happen was...:
Describe what you thought should happen here:

What actually happened was...:
Describe what happened here:i teleported

Steps to Reproduce:
1. going really high
2. ... look at tittle
3. ...