Like you, I had terrible pain going from lower back, thigh, knee (replaced in 2012), leg ankle and foot. Lasted 7 months. Saw my PCP, did physical therapy which helped a little, went to pain clinic where epidural shots helped only briefly, had an MRI and was sent to an orthopaedic surgeon. He said I had spinal stenosis in L3,4&5 and other issues in S1. Surgery not a solution as what would help one problem would make other worse. From research on this site, I learned about stem cell and laser therapy. He was not too encouraging about either. But I was desperate since my husband is not in good health. Chose laser therapy (NOT surgery) after discussion with my vet who has seen positive results in pets. It is done by a chiropractor along with spinal decompression and I have to do physical therapy as well. In 3 weeks I was feeling better. Chiropractor said worst of pain from sciatic nerve. Then, I had a bad fall, breaking my wrist in 4 places, bruising my left rib cage badly and re-injuring an old untreated fracture at the base of my spine. Back to chiropractor 3 times a week and recently adding physical therapy again. I am feeling like a new person. To get through today, you could try ice packs or heat, an over the counter inflammatory if you can take them and, if you cannot reach your doctor, try a walk in clinic. I would not try magnesium without asking a doctor. You might want to consider asking for a referral to a pain clinic or orthopaedist. Hope this helps. Leslie324