I've had a similar response to Neurotin. It simply does not function as one expects and hopes for. For pain management, it is minimally helpful even in large doses. It tends to make me a bit more emotionally reactive than I am otherwise. Think I was more psychologically reliant on its potential 'benefits' than actually enjoying any of them.
One thing I did and would suggest to others is look to Oriental medicine or other alternatives to use in conjunction. My childhood friend is a recently qualified practitioner and suggested I let her try a couple of things. With a couple of well placed pricks, heat therapy (moxa) and massage moves I felt better. Additionally, the cost of these treatments is less than or equal to a refill on some of my prescribed medications.
Sometimes to get total control back you have to give up that which you currently have. For me, this was the assumption that my trauma / neuro doctors were the only ones that could help and that the prescriptions were working. Physically I am not sure acupuncture has actually done anything but psychologically I feel like there has been improvement. Isn't that all that really matters?
Good luck on your journey and I hope things get better! Nerve pain is a terrifyingly annoying thing. Keep us updated!