Welcome @pandep, Earlier in this discussion @lilotter mentioned a doctor in a post, here is the direct link to the post - https://connect.mayoclinic.org/comment/312782/. You are right about it being difficult to find information on some of the more rare types of neuropathy. Here are a few articles I posted earlier in the discussion that I found using Google Scholar (https://scholar.google.com/) that you might find helpful.

Dysimmune small fiber neuropathies – AL Oaklander — "… dysimmunity seemed eminently plausible given the well-documented immune-mediated neuropathies and links … in Boston for SFN associated with autoantibodies to TS-HDS and FGFR3 …and trial existing and new therapies for apparently dysimmune small-fiber polyneuropathy …"
— https://www.sciencedirect.com/science/article/pii/B9780128145722000108

Clinical characteristics of fibroblast growth factor receptor 3 antibody‐related polyneuropathy: a retrospective study — "… fiber neuropathy associated with FGFR3 and TS-HDS may provide further evidence regarding …(INCAT group), Clinimetric evaluation of a new overall disability scale in immune mediated … Dave A, Smith J. Use of Intravenous Immunoglobulin in Small Fiber Neuropathy associated …" — https://onlinelibrary.wiley.com/doi/abs/10.1111/ene.14180

TS-HDS and FGFR3 antibodies in small fiber neuropathy and Dysautonomia: https://pubmed.ncbi.nlm.nih.gov/33792960/

Have you thought about seeking help at a major teaching hospital or health facility like Mayo Clinic?