Hi @robtlhughes
I understand your reluctance to go for the tests, although on balance, I think I would go.
The real issue is what is your final diagnosis. You didn't mention whether you've had other tests. You may actually have a treatable problem which is causing your PN. If so, the sooner you get treatment the better. That may be reason enough for your trip. However, be aware of the fact that a substantial percentage of people with PN are of unknown cause (like me).
As to specific treatment for the PN, you sound like you are aware of the fact that it is problematic, and often less than satisfactory.
I disagree strongly with the poster above who advises that "Lyrica will "definitely help the pain", and that you should try stem cell treatment. Lyrica may help with the pain, not definitely. Furthermore you are already on gabapentin, which is very much like Lyrica. It is important that you are on the proper dose, which the neurologists can help you with. As for stem cells, they are not yet approved for PN (or almost anything else), and trials have been disappointing.
Good luck!