GP's prescribe Prolia or bisphosphonates like Actonel as "first line" treatments which is too bad since you probably need a bone-builder, not an anti-resorptive. The drugs you have been on stop bone turnover but the ones I mentioned actually build bone (Evenity does both).

Respectfully, I think you really need to see an endocrinologist. The need for surgery for stenosis makes this more urgent, but you probably need stronger meds anyway. Insurance can be a problem but you have already tried two other drugs, and I also would look into patient assistance programs. I got Tymlos for free.