As an old-time/long time wedding photographer, covering many FORMAL occasion, I tend to wreck my suits and tuxedos (and mu skeletal and muscular systems) by loading the pockets with gear, carrying heavy flash power packs on my shoulders and getting into awkward positions for low angle shots, etc. So...I have my suits custom made with reinforced extra-large pockets, a little more shoulder padding and strong seat seams. On my last visit to Tony, my favourite tailor, while taking my measurements, he informed me that my right shoulder is considerably lower than my left shoulder. I sarcastically asked him if he was changing his profession to orthopedic surgery or chiropractic. He told me not to be a "smart-ass" and that he would add some extra padding to the lower shoulder.
Point is, after over 50 years of schlepping around heavy electronic flash power packs, hanging medium format cameras around my neck and assuming all kinds of contortions, I managed to deform myself! They say that bad habits come back to bite you in the backside- mine came back to bite me in the neck and shoulders! I feel your pain and in fact, I have it! I work out in the gym, I've had physiotherapy, NADA! At 76-years old, I do have a bit of arthritis and some days, when I get up in the morning, I feel like I was run over by a loaded cement truck.
A hot shower and sometimes an extra-strength Tylenol and I am out of the house and off to work.
The wheel is a great invention so I put them on all my gear cases. I have a couple of collapsible hand-trucks, a giant hockey bag on casters for tripods and light stands and now I put the power pack on the other shoulder- maybe someday they will equalize. No smoking, no booze and cutting down on red meat helps.
I told my rheumatologist that it hurts every time I raise and stretch my right arm- he said "don't do that"!
Face it- we did it to ourselves! I am an old man with a gray beard and the bones and muscles are still operational but they ain't what they used to be. Once the nerves are damaged they're...kaput!
I find that as long as I stay active, the "pain in the neck" subsides a bit and I have no issue with mobility. Bengay helps but the best kind smells like mothballs- that's bad- brigs on ageism!
Get well, stay safe- good luck!