It sounds like we have a similar pain trigger area.
I find good relief from a TENS unit I got through PT. I also learned a trick to make the muscles relax; leaning on a corner of something, couch/wall/or whatever, pushing against the muscle until it gives. It hurts while you are doing it, but it works to reduce the pain once it relaxes. I learned that in PT too. The muscles will fatigue eventually and relearn the softer position.
I do long slow stretches every morning and evening, arms raised, pulling one wrist with your other hand while you slowing bend to the side; then switch sides. All very slow. I do yoga stretches too.
Also try lying on your bed face down with your head & shoulders hanging off the edge for a minute or two.
Don't you hate that crackly sound?! I can't stand it & now other people can hear it. Gross!
Have you tried Arnica Gel as a topical? I get some relief with that too. Mine is an ongoing project it seems. I just keep trying.
I hope some or any of this helps.