Perpetually underwater??

After receiving an update to the game, I'm stuck in a sort of "underwater mode". The bubble graphic appears over the HUD, but I'm on land. I'm unable to touch the ground and I move slowly as if submerged in water. I'm also unable to move up or down or to jump, but I'm still able to crouch. If I fly in Creative mode, I'm able to move normally, but once I stop flying the problem comes right back.