I think BM has it right.
Dental work is a common trigger for TN. If you went to an Endodontist to hve the work done, he/she should have caught that. Anyway, no one has the same story for TN ( I am not as familiar with r.s.d.) it is a very individualized disorder however one of the triggers that can set it off (and a very common one) is having dental work. We are not sure why, some people believe that you already have TN but it is so minor you are not noticing it, or it's kind of dormant (for lack of a better term) and something about the dental procedure sensitizes the nerve.
As for the nausea and other symptoms you mentioned, I've heard that before. Personally I think it's a reaction to the pain not the TN itself.
I've had very similar reactions to severe pain.
See the Neuro and most likely the meds will help a great deal with your pain. Remember though, you may not find the best med for you on the first try, be open to trying as many as needed until you find one that covers your pain well and you can manage the side effects.
I encourage people to give your body time to get used to the meds, these are new to your system and most often the side effects diminish after a few months. So unless the side effects are absolutely unbearable either lower the dose? (always in conjunction with your MD) or try taking the same amount of med daily, only taking it more often (3X's a day instead of 2). These small changes can give you a much better chance of getting used to the med and still getting enough pain relief until you can get to a dosage that really covers all/most of your pain.
And lastly,,,come back here. There is a lot of info and some great people who (between all of us) have seen most everything and can offer good suggestions on how to deal with TN. Once your diagnosis is firm let us know and there are other things you can do to help with the disorder. My last suggestion to everyone...cut out from your diet..aspartame, MSG, caffeine and as much sugar as possible. Good starts in helping with the pain and even if it's not TN, it will help with most nerve related disorders.
Good Luck, we are all here for you....Beth