Have you tried any muscle relaxants? If your pain isn't affected by muscle relaxants, then disregard this suggestion. But if you don't know, you might look into trialing one to see if it helps. And if one of them has drowsiness as a side-effect, it could be helpful.
I second Frederick's suggestion of looking for a way to mitigate the GI issues. I can't take NSAIDs due to the effects on my kidneys, but Mobic didn't bother my stomach. Good luck.
DX: Psoriatic Arthritis, Osteoporosis, Psoriasis
Meds: MTX since Oct 2009, 15mg/week. Cimzia-restarted after 2 yrs away.
Epidural Steroid Injections x8; Lumbar Radiofreq Ablation x2
SIJ Steroid Injection x3; Bilateral Radiofreq Ablation SIJ x9