Sorry you are still in a lot of pain, Cazikins.
I haven't had any experience of a PCC, however I am sure I've seen that they use TENS machines, acupuncture and other treatments, so it isn't just hypnotherapy or relaxation. Also they may be some very gentle exercises that they can suggest. I've had some acupuncture on my lower back recently along with massage there has been some improvement.
There was a clinic at the hospital where I used to work I've just looked it up and as well as TENS they also mention neuro modulation ( whatever that is). They give 2 links Action on Pain and the British Pain Society Flutterbyx