Hello Ian....

I have some questions.

What was going on with you 5 months ago? Vaccines? Illness?
Did you start some new routine like exercising, or did you go on a vacation somewhere? Were you exposed to solvents doing any task or woodworking?

Have you had thyroid testing?

Have you been to a podiatrist and been evaluated for any foot problems...spurs, sesamoid bones, ankle issues, pronation, neuroma, etc?

What drugs do you take? Statins? Did you use any antibiotics just before or during the onset of your symptoms?

What is your diet like? Are you a vegetarian? Do you eat fast food alot, or processed foods? (may contain high levels of MSG).

Do you take any vitamin or mineral supplements? Before this onset did you take any?

Do you get digestive upsets frequently?

There are over 100 causes of PNs....one has to be a detective of sorts, to figure things out and some doctors don't spend that time with you.

You need to tell us more.