(eta: I did check the temp directory, which only had a couple obviously Word files in it (and other things I randomly opened were gibberish or empty), with no luck. I don' tknow if there's somewhere else temporary files appear...?)
(eta again: Nevermind. Turns out the stuff I lost was modified from part of the original manuscript (which explains why I had no clue what I'd written: all I'd done was make some very moderate changes to existing text. I can do that again without an issue. Whew. Also, boy am I glad I didn't come make a flaming screaming idiot of myself here only to discover this mistake three hours later... :).)