Fortunately I have no pain since I've been on the B12.
My gait & posture so far hasn't been affected.
Although if this problem with the Coccyx gets any worse I may have to sit differently.
My main worry at the moment is my right hand. I still have full use of it but it is getting very unfeeling. When I am typing now I have to look where my fingers are going. Also I find some Dyslexia coming into my typing.