Clunking in mid/upper back around scapula region

Hello, posters.

Injury:
I had an injury during my early teen years.
I fell off a top bunk while sleeping and woke up to find a pain in my mid/upper back, left side, around/under the scapula region.
Never got it checked out.

Symptoms:
A clunking noise in the area I described (mid back, near/under scapula)
While moving my left shoulder from front to rear for a full movement, I can sometimes hear 2 deep clunks.
Right side no noise.
Pull ups, handstands cause no real pain.
However, the muscle (rhomboid) often aches and feels sore about 12-24 hours after moderate exercise.
I think my levator scapulae and rhomboids have the most pain

Treatment:
I have had about 12 deep massage sessions.
Some feel like they have made progress, but sometimes I feel the massage has increased the clunking, and soreness.
X-ray revealed no signs of injury.
The massage therapist says it will hurt for some time as scar tissue needs to be broken up over several months.
Heat can ease the pain, temporarily.

Questions:
Should I continue deep massage once a week, and expect some pain now and again until finished?
Is it a scar tissue problem? Or fibrosis?
Anything else I should note?

Thanks!