Persistent pain that does not show a corresponding link to disc or spine problems (which would be seen on x-ray, MRI and CT) can be very difficult to diagnose.
Pain lasting 9 months without relief is frustrating and exhausting ---
What have your doctors recommended other than taking pain medication? Has there been any type of discussion regarding muscle fatigue? Fibromyalgia?
The spinous process being sore to the touch could be related to referred pain from the adjacent muscles/ligaments etc. If you are not noticing any significant neurological changes (numbness/tingling), a myofascial pain syndrome seems a likely possibility.
Trigger point therapy and possible trigger point injections may be helpful.
Discuss this and other muscle related conditions with your doctor. He may not think it is related, but a thorough exam and clinical testing for trigger points might get the relief you desire.
Post again with an update ----