If your back is in that much pain, maybe you should see a different doctor. However, if going to the doc isn't helping, perhaps someone in your club has some experience with the touch for healing arts i.e. shiatsu(can be very effective), acupuncture(?) etc. Or maybe, if you are able to relax and stop training for a few days, it might get better on its own. It's no fun having a sore back, hope you feel better soon.