welcome to lybrate
you seem to be suffering from acute muscular pain
. I would advise you to get a x-ray cervical spine to rule out any disc prolapse.
For acute muscular pain I advise following:
1. A combination of pain killer and muscle relaxant containing diclofenac
2. To do hot fomentation of the affected area.
3. To apply diclofenac ointment locally.
4. To get physiotherapy
done particularly ultrasonic heat massage.
Your pain would start getting better in 5 days.
If any disc prolapse
is found you would be treated with a combination of pregabalin
and methycobalamine. Share my opinion with your doctor before you act upon it. I hope it helps.