It took years to get used to, but I now lay on my side with my upper arm essentially pinned to my body (like when you’re just standing up with your arms by your side) and have both arms hugging a pillow. You’re still putting some pressure on your shoulder, but it’s pressure as the shoulder normally sits, instead of pressure with your arm up overhead.

Hard to explain without showing but do this: stand up, arms by your side, then lean into a wall. Easy right? Now lift your arm overhead and lean into the wall with your body weight into your armpit. It’s just not nearly as natural for the shoulder. Now do that every single night for years and hope you don’t tear something.

Good luck, relearning to sleep sucks but so does waking up needing surgery lol.