There can be metabolic causes for neuropathic pain.

There can be things in your environment, that damage your nerves. You may have inherited a genetic problem called Charcot Marie Tooth...which has many variants, and presents differently in different people.

Your dose of Trileptal was high, IMO. Most dosing scales you see are for patients with seizures. Those will tend to be higher than for other purposes.

You said yourself, that it didn't work that well, but it did work "some".

The side effect profile for Effexor is no where near as serious as Trileptal's.

The serious side effects begin with time passing, and 5 yrs is a long time to be on this drug. Other anti-seizure meds work better on nerve pain, and have far less toxic consequences.
Lyrica, Neurontin, and Topamax to name 3. When you get the toxicity for Trileptal it can be sudden and severe. Hyponatremia strikes quickly.

This is our PN forum. Above it is the informational posts in a Subforum context.
http://neurotalk.psychcentral.com/forum20.html

I think your quality of life is important. And if you want to do some homework you may find your cause and treat that. Just taking toxic drugs to cover a symptom, is dangerous and over time will cost you some aspect of your health.

No one here can tell you anything about your doctor. But some of us have experience with pain, and neuropathy, and can help you find the best solutions to it. I do not think your new doctor is untrustworthy. I think he/she is looking out for your future health.