It’s not clear from the article. What was author diagnosed with? They said it was an injury…
As someone who went through a similar experience, I would not be surprised if the author's pain is/was entirely psychosomatic (this doesn't diminish its severity or significance). Probably a direct result of burnout.
It sounded like rheumatoid arthritis.
I don't know about RA. OPs blog post sounds a bit too optimistic for someone living with untreated RA for 3 years.
closest thing people gave me was DQT but 10 months of PT didnt help and MRA / XRAY found nothing