When you're physio did mobilizations on your back and your pain went away, that's a pretty good sign that you have a mechanical issue going on, as the pain can be made to go away.
I'm assuming that your 'memory pain' is what is often called chronic pain. It usually doesn't just go away...
Go back to the physio that helped you out at the hospital. I think you're on the right track with the treatment that physio did for you. See if that physio can recommend someone for you to go to that does similar work. And try that.
Interested to see what theMRI results show.