"The treatment protocol for TMS includes education, writing about emotional issues, resumption of a normal lifestyle and, for some patients, support meetings and/or psychotherapy"
For general back pain, I wouldn't be surprised if this "treatment" involves some very simple stress relief mechanism that relaxes muscles and reduces muscular pain for some people, some of the time.
The theory, however, is nonsense, and you could just as easily substitute "demons" and "exorcism" for "emotions" and psychotherapy" and get the same results. "TMS" is a made up term with no science behind it, just wilful speculation from a professional who should know better.
To suggest it has anything to do with the unremitting pain described in the OP is deeply irresponsible. It's like suggesting homeopathy for cancer. In fact it's probably worse, as it amounts to victim-blaming because the patient isn't dealing with their "repressed" rage/emotions. Awful.