is it small fibre neuropathy? (SFN)

is it possible I don't have SFN? My diagnosis was, in my opinion, a bit iffy. No test was done , like a skin biopsy. Other possibilities were eliminated though, like large fibre neuropathy using MRI scans and a nerve conduction study. And the neurologist specialised in dementia with general neurology issues dealt with in addition.
At present I am receiving no treatment, My feet are my problem with my left foot by far the worst, including ice coldness, sometimes burning, always tingling etc. I have signs of foot drop too plus a lump, or swelling has appeared at the bottom of my leg just before the foot.
I was then told I had adult onset fallen arches, collapsed in my left foot.
Lo and behold , when I googled these symptoms I got tarsal tunnel syndrome( or compression of the tibial nerve). I was amazed. That's what I've got I thought !! I was seeing a podiatrist( using National Health Service(NHS)). After an ultrasound and 2 MRIs on the lump area I'm no more the wiser. After the first MRI I was told it could be a swelling on a tendon but come back in 4 months for a further MRI. I did this and am totally unclear about the nature of this lump. I did explore my theory about TTS but that was rapidly kicked into touch. " You have small fibre neuropathy" I was aggressively told.
I bought custom made insoles to help symptoms of my fallen arches---pain in the legs in particular. They did help the leg pain but my parasthesia in my left foot seemed to worsen plus I had to but shoes a size bigger than my size. Asa cynic I can't help but wonder if money is more important than a proper diagnosis.
I made a decision recently to find out more about TTS. That led me to arrange a consultation with a Foot and Ankle specialist. He is an orthopedic surgeon too. And deals a lot with professional sports people, footballers, rugby players etc. I am not a professional sportsman, never have been but was very active over the years---football at top amateur level, league table tennis, cycling and more. I only recently stopped league table tennis, still cycle and go to gym.
I told him my symptoms and and that i had been told I had age related peripheral neuropathy. He said he thought I had tarsal tunnel syndrome. But my choice was to either put up with it or have surgery to decompress the tibial nerve. I was initially elated to have been right about this. I do have medical insurance but, after the consultations with neurology at considerable cost and suffering a huge hike in premiums I chose to switch Insurers. I thought the help I was getting from the NHS would cover me in future on the foot front. So I would have to do this as a self funded exercise. Not a problem, especially if it helped my foot issue.
Doubts have since crept in. He didn't call for any tests for example.Maybe a bit matter of fact. Money motivated?? I asked if I should try physiotherapy but he just said " put up with it, or do surgery"..
I'm now trying a few physio exercises to help TTS, to relieve pressure on the tibial nerve. I may be too late of course as I've had this for 5 years. But I'm still a fighter. I've 3 holidays coming up and need my legs..