Most of my shoulder issues are sleep related since I sleep on my side. Getting a body pillow system, was costly but kinda worth it. Helps with shoulder and GERD. Only issue is that it's kinda warm and I like to sleep cool.
It's not perfect, but has really helped me!
And yes, try not to eat right before bed. Especially greasy food.
This doesn't inspire confidence, but I guess any improvement that mitigates pain is nice.