Update:

I almost feel bad reporting this good news since so many of you are continuously suffering.

Prednisone seems to be helping. After only 2 days of taking 60 mg daily (still have 5 days to go), I can feet my feet! I weirdly have tightness in my upper calf (that's new), but very little lingering tingling or numbness in my feet.

Still don't know the root cause. Could be pinched nerve, inflammation from vaccine, etc. Either way, knowing it can reverse is amazing. I was fearful that whatever was happening was permanent and would only continue to crawl up my legs and worsen.

Thank you for the support. I'll continue to update as I finish my week of prednisone.