Hello and Welcome to HCM,
Thanks for writing to us.
It seems that you had a muscle pull at neck.
You should give proper rest to your neck and shoulder. Do not lift heavy weights over it.
Antiinflammatory and muscle relaxant
will provide some relief.
Take medicines under medical supervision only. Hot fomentation and application of local pain relieving gel will be helpful.. I suggest you to consult an orthopaedician nearby for a detailed examination. You may get the X-ray of the area affected under his/her guidance.
Hope this helps you.
Wishing you good health...
Dr Saurabh Gupta.Orthopaedic Surgeon