For the past few days, I've been working on building a structure in Minecraft. I usually open it up to LAN when I get on so that my friends can help me. However today, I decided to create a /kill @e loop (stupid mistake #1) when it was not yet opened. In panic, I decided to look up how to fix this so that I could safely re-enter my world. I decided to switch to 1.7.10, where command blocks were not yet in the game. When I opened the world, it didn't recommend me to make a backup, so I didn't think I needed to (stupid mistake #2). However, once everything had loaded in, I couldn't find the structure anywhere, not even at the coordinates where it was being built (and it was 16 x 16 chunks, so definitely noticeable). How can I (hopefully) recover it?