i cant play the game properly

I tried to play my game and the world was loading up as I spawned the whole world just started to move about and I couldn't see where the stuff I built was

What I expected to happen was...:
I should just be able to play normaly

What actually happened was...:
the whole world started flying about everywhere

Steps to Reproduce:
1. all that happens is you log on to your world and it flys about