Hello PepperCross, I don't live in the US anymore, so the only treatment center for ketamine that I know of is in Tampa, FL. Just google treatment center RSD Florida but I think they do a lot of ketamine treatment.
The worst thing for RSD/CRPS is inactivity; I'm afraid that the repeated wearing of the boots, especially when the foot was abnormally painful, precipitated the RSD. Unfortunately, some orthopedists don't know much about RSD.
What the doctors were doing with the nerve conduction test, MRI and bone scan was ruling out everything else which is the way you diagnose RSD, so they were doing the correct thing.
The lumbar blocks are not a cure for RSD. They help diagnose the RSD. If the pain responds, then it's more likely to be RSD. The purpose of subsequent shots is to enable
you to do physiotherapy which is the best treatment for RSD. After a time, they cease to be effective and are usually stopped.
Forgive me for calling it RSD: I was diagnosed before the name was changed to CRPS and it just comes easier. They are the same thing.
Check the RSDSA website for support groups, they have a page on it. You can also phone them. You could put your name forward as a contact for your area and set up a group when you get replies.
Set up a Facebook page with CRPS or RSD and your area in the title and I'm sure you will eventually hear from people. A friend of mine did that successfully.
I'm really tired right now, it's after midnight here (in Ireland) but I promise to get back to you again at the weekend with some more ideas. My RSD began in my L ankle too! Paula/cailinruaidh

Forgive me