Build Mode Has Disappeared

So I load in to the game, and everything seems fine (I can go in to manage worlds and everything) but when I press the button that gets you in to build mode everything is great except for the fact that the build mode menu has disappeared. All I can see (other than what the game would look like if you pressed "tab", idk how to explain it) is the bar in the top left of the screen. I can get back in to live mode and then when I'm in live mode everything is frozen. I am very desperate and am willing to try anything short of ritual sacrifice