After a day to calm down from the initial shock, a more objective assessment of the damage is that it isn't as bad as I had imagined. Although I gave up the old molar for lost, it actually is still mostly there... except for about a quarter that's been temporarily filled in with spackle or whatever they're using. That would explain why when the dentist tried to show me the fragment that she'd extracted -- fell out, more like -- I was all like, "where's the rest?" to which all I got in reply was a mystified look.
The temporary crown has the consistency of sandpaper, though, and because it's the most unusual thing in my mouth, my tongue is rubbing itself raw on its surface. :p