omg, the exact same thing happened to me making my gameboy game, ended up paying a data recovery place $400AUD to recover my harddrive just to pull the game files from my desktop. What are the odds!
It's why I backup everything I do, even if it's a few sprites XD I ent risking that, I've had enough of that even before I was making games. Wierd that people don't frequently back up stuff? Tech isn't invincible.