Chronic Low BP With Numbness And Tingling In Toes, Xrays Inconclusive, Prescribed Chlorzoxazone, Nabumetone, No Help. Second Opinion ?

I have chronic lbp w/ numbness and tingling in toes, pain reaches down the back of my thighs and generally stops behind the knee. I am in general good health, no daily meds, occasional sinus infection . I have done physical therapy , taken x-rays which are inconclusive and show no degenerative disc disease or areas of concern. I have been prescribed chlorzoxazone and nabumetone, which offers no relief and only aids as a bandaid. Is this something that I must learn to deal with or should I seek a second opinion and request an MRI or something else to be more conclusive? I have constant pain whether sitting or standing. I am elementary school teacher which requires constant bending, lifting, standing, sitting, and good mobility in the classroom. Any help would be appreciated. Thanks!