But, your avatar's an imp. >.>
Seriously though.......@OP, your last save, even an autosave can't be THAT far behind you. Even if it's a couple of levels ago, it's not that big a deal. The game isn't THAT long. I've restarted the game twice now because for some reason, I just can't backtrack through an earlier save. It's frustrating to miss something, load an earlier save, get the thing I missed only to find the person I had killed AFTER missing something was dead already when I arrived there again so I was unable to continue playing through because, ya, guess what? I couldn't do the mission over again despite going back 3 or 4 saves before it. Just take a break from the game, and chill, come back to it again later.