This patient support community is for discussions relating to Dysautonomia (Autonomic Dysfunction) including: Postural orthostatic tachycardia syndrome (POTS), neurocardiogenic syncope, mitral valve prolapse dysautonomia, pure autonomic failure, autonomic instability and others.
I have read a bit about PAF but don't know too many specifics about it's diagnosis. From memory, it sounded a bit like a diagnosis of exclusion... meaning once most other possible sources of neuropathy have been excluded then one concludes that it is simply pure autonomic failure. Your symptoms do seem like that is a possibility. Also, POTS is often (most often?) lacking a distinct known cause and I think it can encompass much of what you describe.
If you are having clear neurological developments then there is a chance some neuro testing can turn something up. Also, be sure to do a "poor man's tilt" on yourself and seek a tilt table test to pin down the pulse increase of POTS definitively. Depending on the pattern of pain, fibromyalgia can be considered and it has similarity/crossover to POTS & CFS. Endocrine issues probably need to be considered, they can throw up at least several of the symptoms you mention though perhaps not all? And if there are signs, autoimmune sources of neuropathy should be sought out.
Bottom line though, if a doctor says there is nothing wrong but you know better, you have probably reached the end of the line in their abilities and need to seek a new doctor (usually a new combination of doctors) for these sorts of conditions.
The catecholamine testing is a good start and has implications regarding several different possible diagnoses including POTS.