glitchy &a lag...

i recently updated and the most of the map wont load after a few minutes of playing on it. i can see the cave system and just white under the upper part of the world and the blocks start shaking and i cant move, then everything goes white. please fix this (AND the lag!!!! im guessing it happens bc of the lag) & ill give full stars bc im satisfied for the most part besides that.

Fire rules about Minecraft: Pocket Edition, v1.1.5