I tried to apply X (my pickaxe) diagonally up-left. Unfortunately, I wasn't paying close attention. The apply function was skipped (I guess the 7 key corresponds to Yes) so now I'm in Explore mode. I don't know how to exit Explore mode.

The wiki says "Once in, forever in" but it also says something about keeping the old save file when you restore a game. I don't understand what this means.  

I want to play this character through, am I screwed? Is that save file a way to return to normal?  If there is a way to get my game back could someone please provide an answer.

I haven't moved since the message "You're now in nonscoring explore mode". Maybe a chance to make bones file, I absorbed 2 bones to get to this point. It would be shame to waste all of that and the time it takes an ARC to get there.

My PC sleeps until I get an answer.