Hi help,
your condition sounds like ribs to me. All the symptoms you describe in your last post fit the picture.
XRays won't show a rib problem like what i think you have (myofascial/motor control/articular dysfunction) unless there is an obvious fracture. nor will any other scan.
It will take a physio or chiro or osteo trained in movement dysfunction of the thoracic spine - there aren't many around.
It is learning how to use the small msucles around your ribs that is important.
Good luck!