The neurologist will check you out and hopefully can help you with some simple explanation - we all want simple, right? There could be various explanations and it is possible the two issues aren't related, even if it seems like they are.

I have migraines and at times they have been bad enough to be similar to what you describe. I also have trigeminal neuralgia which sounds a lot like what you have. I have it mostly on my right side, but get it on both sides of my face. It is supposed to be the most painful thing you can go through, though I have been through worse. If the neurologist finds that it is TN, there is medication you can take. Mine is worse in the winter with the cold air.