Everything in my chests, inventory, and furnaces is gone. All of my items have disappeared.

Everything is gone. Everything Ive worked for and put time into is just gone. I logged into my minecraft world that has been on Minecraft snapshot 14w30c and all of my items disappeared. My chests, furnaces, and my inventory was completely empty. Please have this fixed, I just gained interest in Minecraft again with this new update and everything I got excited for just vanished. :/