AW!
That sucks.
Im a grinder, I wear a mouthguard too, its one from the dentist, so its molded to your mouth and won't come out when you sleep.
You're sure its not something stuck in your gums, like wayyy up in there. Also happened to me, went to the dentist cause it was o so painful, I couldn't put any pressure on it, or chew, or anything. Well anyway it was a popcorn kernal. Stuck way up in my gum..she dug it out with floss.
Have your wifee look at it closely and see if she can see anything.
You can go to any walk-in and they'll give help you best they can, at least give ya wicked pain killers to last til Monday.
Good Luck!!