So sorry about your dental problem.
The likeliness that you have two teeth or areas bothering you are quite slim, as you mentioned both top & bottom pain. So, presumptuously, I would tend to think your pain for both top & bottom are near the rear portion of the mouth. The rear area, can and often tends to lead, more often, to having pain on the top & the bottom both.
The very best news, is you have made the Dental appointment for tomorrow! As it is impossible for me, without an exam or x-rays to determine specifically what the problem is. But, it could be one of several things, anything from some tartar build up & annoying your mouth , gums, etc., as well as a possible abscess?
Again, I do NOT know the cause of the problem. But your Dentist tomorrow will almost undoubtedly be able to fix & rectify the problem, whatever it is. So, I hope this helps you, at least a small amount... and I indeed wish you all the best tomorrow.
I feel confident that by tomorrow, you will feel much more relaxed and realize that this can be & will be fixable and you can soon return to normalcy!! All the best to you. Dr. Rampton