It is due to strain. Please avoid a large pillow while sleeping and take comfortable position while lying on bed.
You can take Diclofenac
Sodium as fast reliever with the combination of muscle relaxant
such as Muscuril for 05 days. You will be fine in 04 hrs of first dose.
I hope I am successful in solving your query if you have more you can ask me.
Dr. Azhar Sattar