Can try vasoconstricting nose spray, e.g. Afrin or Neosynephrin. May work faster than finding a dentist or physician on a weekend!

My sincerest thanks for this advice, as well as to others who suggested it might be a sinus problem. The pain had gotten really intense, and I remembered that I did have some nose spray upstairs. Two squirts up the side with the pain, and the piercing pain went away almost instantly. It is still a little sore, but before the nose spray it felt like I was undergoing a root canal with no anesthetic.

You're more than welcome. Glad you tried it. Often the simplest solution is the best.