Greetings, sorry about the pain. Lying and turning in bed should be a trouble for you I suppose, then Poor posture has created shoulder blade pain.
Next Steps
get to see a physio with knowledge about trigger point therapy and posture correction. 60% of your problem will resolve in 3-5 days and with stretching and strengthening exercise rest of pain will go away in 10 days time or even less.
Health Tips
if any questions do let me know.