Osteo1, do you mind if I email you? I don't know a lot about Osteopaths and it could be the next step if it sounds better than the physio I've had.
Totally agree that core strength is central to the problem, but the mattress was making it worse IME. I'm certainly in less pain than at any time for the last 3 months, when I finished the last treatment.
Hopefully core exercises will be possible without leaving me in severe pain now. I've had plenty of excercises to do and seen two physios and a chiropractor. Do you get some kind of bonus when you complete the set if I go for an Osteopath?