Back pain between shoulder blades. i didn't fall or carry any heavy loads. even more painful when i sneeze or cough?

? Cervical disc : Problems, try to rest and avoid lifting heavy objects, take NSAIDS, unless contraindicated, if no improvement see your doctor for assessment and possible referral to a spine specialist, wish you well

Pain btw shoulder: Would also consider GERD as I have seen scapula pain with it, rarely vascular ( you seem young for dissection), or cardiac (pericardial effusion). Would f/u/ w/ doc today if it is unremitting.