Your experience sounds very similar to mine. Checkout the recent thread, "Doc says no SFN, I don't believe him"

My experience started with mild pain and tons of fasciculations or muscle twitches. One doc suggested SFN and another BCFS or benign cramp fasciculation syndrome.
The symptoms started out mild and intermittent. One day they were there and the next completely normal.However, they progressed rapidly over 6 months. Sometime after, something changed and it got progressively better. However, my pain has stayed the same and my twitches are still present. After continually asking for a skin punch i finally got it and received a positive diagnosis for SFN a few weeks ago.

My advice would be to set up another neuro appointment (you can always cancel) and monitor how things are going. Push for the skin biopsy for peace of mind.