Lava won't kill & respawn you - you get stuck

I created my first portal to the Nether and was unfortunate enough to get spawned mid air above lava. I fell into the lava but instead of dying, I'm stuck - literally no where. You can't move anywhere, your health doesn't deplete, and there's no way to get back to the overworld. I've died from lava and fire spits before & rebooting the computer and game has currently made no difference.