I too used to get terrible shoulder pain. I am lucky because my partner would massage the rigid knotty muscles in my shoulders and upper back...the massage was very painful but it would work great for a couple of days.
While I was being massaged I would belch up huge amounts of wind, so much of it, I hardly had space to breathe in between the belches, the wind was almost a constant flow. Not only would my shoulder muscles feel better afterwards but my brain fog would also clear at the same time.
So your shoulders could just be trapped gases. This sometimes happens to people who have had surgery. The air/gas collects in the shoulders. Candida causes gases ( I have just read this on the net), and its got to go somewhere....if not expelled, upwards, high point: Shoulders and head/neck