This does seem quite complicated too, the lumbar vs cervical spine issues vs the machine etc....
Have you written out a time line and how symptoms & pain have changed all this time?
Sometime journaling helps to clarify points and also helps to unload some of the stresses once they are on paper.

I tried a similar machine for a short time, but I didn’t care for the confinement and forced use...seemed like overkill to me..unnatural...