Congratulations on your recovery @bachissimo !
I know of John Sarno, in fact I read his books when I had a major backpain episode about 12/13 years ago. I found the connection between the brain and backpain fascinating, but it did not help me at all. What helped was a 2-week backpain rehabilitation with lots of exercises every day. I am still doing some of these exercises.
Interesting that his thinking helped you with your MAV/PCS. Is there anything in particular that helped you the most?