Hi Dave!

Welcome!
Sorry you have been in pain.

I am very "rusty" at this.
Fortunately, others will be along to help!

Have you had a skin punch biopsy?
This would look at small fiber nerves.

Are you gluten intolerant?
Any meds known to be neurotoxic prior to/during the onset of pain?
How is your circulation to your lower extremities?
Any discoloration when your feet feel cold?

I assure you that others here will pose better questions!
Great group here!

Welcome to the forum!
~DejaVu