Wow! Sorry to hear about your shoulder! I hurt mine a hundred years ago and it's been weak all of my life as a result. I keep injuring it periodically. It hurts when I sleep also and sometimes wakes me up, or keeps me from deep sleep.
I started this summer working with a personal trainer, who is also a physical therapist and he's been working with me to help strengthen my shoulders with exercises for rotator cuff injuries. I searched online and what we're doing during my training is what's prescribed in most of the medical websites. Simple-stretch band exercises have helped quite a bit.
I have had to change my sleeping position too. I used to hold my right arm up over my head and rest my head on my forearm. I can't do that anymore.
There are also some good stretches that seem to help.
Best of luck in your recovery! I hope it feels better soon!
Height: 5' 10"
Starting Weight: 292
Starting Primal Weight: 275
Current weight: 230
Goal weight: 172
Body Fat 27.5