I, too, have gone off to the rest room for a cry. Just wait it out, splash some cold water on your face. If anyone asks what's wrong, tell them you had a sneezing or coughing fit.

Don't worry about what they think. If they noticed something the day before, chances are very good they're not going to say anything the next day. If they do ask and you don't want to answer, just tell them politely that you'd rather not discuss it.