I had that several times when I was exhausted and unwell. I thought I might lose all my teeth.
It passed, eventually, after a night of weird pain. Some acetaminophen helped enough to allow me to fall asleep.
My suspicion was inflammation from MPN, as I saw a dentist earlier and things were OK.
If you can see a dentist in the near future, that would be safer.
Also, if you are taking cytoreductive medication, this pain can be from it and probably your MPN specialist can help.
I take only baby aspirin, and in that context the pain was very weird.

I have never had thad I only get a very dry mouth

Thank you so much, Eugene and Tia. The pain has lessened a great deal, and I am grateful.

That must be so painful 🤗