No need to explain, perfectly understood.
It’s possitively exhausting.
You know, before I had my meltdown around February of 2017, Marcus was having RC issues and mentioned some things that he was doing (HIT thread). Think he was lying and rolling on a roller or ball & stretching at the same time.
Also consider a chiropractor whose massage therapist can work on your shoulder, neck & mid-back. Then have him adjust and loosen up the neck & mid-back. That should get the pain out of your arm.