Minecraft xbox 360 world restarted?

I saw their was an update for minecraft xbox 360 edition, however i didn't want to update yet so i went to the home menu. I went back to minecraft and then i saw the menu changed, i thought nothing of it because i thought it might have just changed that much. I then loaded up my main world (which i have worked on since tu1 or 2) only to be put in the middle of nowhere on a completely different map without any of the things i had built. I was getting a little worried since i had put alot and i mean ALOT of work on that map. So i went to the xbox home menu and turned off the console and went back to the game to see that the menu was back to normal (it updated first and i let it update, but it didn't add anything in fact it just said it had added the things from the previous update) so i loaded up my main world and i was put into a new world again. You can still see a small picture of the world on the side, but it still starts the world over when you select it. Is their anything i can do to get the old world i had worked so hard on back?