Bob, I have been in a similar position to you since last October. Have always had back problems of various sorts but since October have been suffering from sciatica and other leg pains and have been almost unable to walk. Have had some more Xrays, but before going down the MRI route, and knowing my fear of hospitals, my GP arranged for physio sessions and they really are helping, slowly but surely. I would not want a back operation unless it was essential, they are considerably risky. I am now walking, but not without discomfort and some days are better than others.
I would seriously consider asking your GP if you could be referred for physio. You might be pleasantly surprised at what they can do. I wasn't at all confident that it would help me at all, but it has.