I might have a synopsis in the intro sticky thread, way back 2006 or so..
past concussion & /whiplash
assembly work 10hr days x 15 yrs.
reaching & arms up , head forward positions often

best helps
Sharon Butler RSI & TOS stretches ( www.selfcare4rsi.com )
trigger point self work tennis ball, golf ball , dog ball etc on floor or against walls.
top rib mobilisations
expert /healing chiropractor
lots of home focussed self care far infrared heating pad, IF stim, gentle stretches
being careful to NOT push past in to pain , slow & easy baby steps are the best way or face flares & set backs.