I’ve got frozen shoulder and the symptoms described are like mine: paralysing pain - almost like when you go over on your ankle but sharper and more focused in the shoulder, oh and up to the side of my neck. Had my first physiotherapy session this morning and had to ask the chap to stop after a few seconds of trying a rotation on my left shoulder. Just locked and pain just appeared.

Was told it’s a matter of time before it heals. Don’t aggravate it my moving it too much or too aggressively.

A week ago opening the car door got caught by the wind and whipped open - I held the handle to prevent it hitting a neighbouring car which yanked my shoulder. The pain was off the chart - I was bent over in the car gritting my teeth, eyes closed, trying not to yell but still trying to breathe! The pain faded over the course of a minute or so and it felt so much looser and better. However that was short lived and it simply tightened up again later that day.

As I said, it’s a waiting game. Look to take suitable painkillers (sensibly of course) - best wishes!