Im no expert Elsie, but it sounds to me that you have pulled a muscle somewhere between your shoulder blades, If you cant tilt your head back or from side to side, this may have trapped a nerve too.

Ive been there and done that Elsie, and its awful. If you have got someone to massage it out that will help, take a couple of paracetamol too.

Unfortunately, this takes a few days to settle again.

Good look at the Drs.