strange, but true
I also suffer from this condition. I donnot have gbs/cidp and in my case it is not related. ( carer to daughter w/cidp)
For years, I have dreamt of sleeping on a diving board – with both arms suspended down from the shoulders, hanging in mid-air. Often I sleep at the edge of my bed in this fashion to relieve the pain one arm at a time. My problems are (suspected) from a car accident in which I had shoulder/neck/back injuries from the seatbelt. I’ve had offers from a neurosurgon to have surgery on my shoulders (forgot the name to the muscle/nerve structure specific to this), but am too chicken for the procedure. At any rate, mabe my experience will give you some insight into the cause of your discomfort.