Welcome to the forum - I'm new here as well.

I don't have much experience other than my own: I had severe pain in my feet, in the heel and arch. Diagnosed as plantar fasciitis, although the symptoms didn't match perfectly. The pain would be so intense that I couldn't walk, or put any weight on the foot, at times. It started with the right foot. Lasted for a couple years, then suddenly one day, with no treatment it stopped.

Then it popped up in the left foot. Same symptoms, other side of the body.

Turned out I have a nerve impingement in the lumbar region. Treating that has helped me a lot.

I hope you find some relief.