So, on my Single Player Survival World, I had a few chests and furnaces and things and they had some pretty darn important stuff in them including all of my iron, food, etc. So what happened was I got onto the world and it started lagging kinda weirdly. It was like normal (50 fps) and then every like 3 seconds it just froze and the only way to get it to stop was to use Esc. It went on like this for a long while until i decided to go back to the main menu and try again, but when I got back I found that my inventory and all of my chests were wiped clean of everything (except anything that I got after I got on again.) It was really spooky and I really want all of my stuff back because it was my best survival. Please reply if you have had any experiences like this or if you know how to fix this. (this was all in 1.7 by the way and I hadn't touched it with the snapshots or mods or anything)
All Items In Chests, Inventory, And Furnaces Gone O.o