How hard do I push for a diagnosis?

I feel like I have been through the mill with what I call NHS speedmedicine (like speed dating - you get 5 minutes to make an assessment then move on to the next person). I have seen a lot of different doctors - but each one has just looked at one tiny part of what feels like a systemic problem, done rather random tests and then referred me back to GP. I have a huge family history of all sorts of autoimmune disorders including RA, AS, crohns, thyroid, coeliac, and have been diagnosed coeliac disease. I am seronegative for the usual rheumatology blood tests, including all the extra tests for lupus (done because of a classic malar rash). Biggest problems have always been where muscle joins onto bone, down spine, sacroiliac joints, ribs. Major lower back muscle spasms +bladder problems led to neuro referral and when it wasn't neuro I got told variously somatization disorder, CFS, fibromyalgia, and chronic pain syndrome. My cousin has AS, my father and brother have similar problems to me (undiagnosed), I now have pretty much zero chest expansion and can barely touch my knees when I bend over. My SI xrays show some sclerosis (very vague report though) but GP says its not enough to explain my pain. NSAIDS relieve things, but not enough now. I'm in my 50's and female, but have had back and SI problems since I was in my teens. I am also getting increasing gastro. problems not related to the coeliac disease.

Do I just accept fibromyalgia, take NSAIDS and grin and bear it? Or do I push a bit harder to get to see a rheumatologist again, bearing in mind the first time I saw one it was on referral from dermatology with ?lupus (Rheum. said not systemic on basis of blood tests). Second time I saw NHS rheum. it was with a file full of psychological reasons for all my problems and he only gave a cursory exam and sent me back to GP.