kaazoom - sorry you are having all these problems, I had various tests, including an endoscopy (camera down my throat to the stomach), and nerve function tests, ie the fibre thingy (sorry) touching my feet, legs, arms, the tuning fork testing for reflexes and vibration test.
Then I had nerve function tests where some cables/electrodes were attached to feet, elbows, arms and hands and this produced something similar to some graph you get when you have a ECG.
None of the tests are painful or uncomfortable. My neuropathies have almost disappeared now, plenty of hard work learning about diabetes, blood sugar control keeping numbers at non diabetic levels, specific exercise routine to strengthen limbs (Theraband) and medication that was prescribed by an alernative practitioner, medically qualified I might add.
The NHS only offered symptomatic relief, although I hasten to add that at the time I was most grateful for that.
I hope you find something that helps you feel better once more.