Help, Cant Move

Been playing for a while, once randomly played and my character wouldnt move, i can look around, use tools and everything just cant move. what should i do?

Theres been a problem with minecraft lately, its been bugging out on me too. Sometimes I cant move and other times I'll save and then end up somewhere totally different when I log back in. They're working on it atm, actually since a couple days ago.