I couldn't believe it, but I was told several years ago that my back pain was severe spinal arthritis. It is really very bad, I've seen the X-rays and I only have about 4 vertebrae which are not suffering. It was all complicated by hips disintegrating and needing replacement etc., etc.. I finally found a good physio/osteopath who has rendered me pain-free for at least the last 3 months, so I recommend that route.
You will, like me, need treatment from time to time, for the rest of your life. I've not had any for over three months (after being signed off after 2nd hip replacement) - I'm only 65 and was very, very healthy and athletic; 3rd in UK for over 40's High Jump! At least I am now walking the dog etc. and am pain-free. It can be managed, so be encouraged.