the history is provided is not adequate yet i would try and give you brief idea about such injuries. the injuries of neck and shoulder are closely associated and pain or injury in one can cause the loss of function and referred pain in the other region too. first you need to take in get yourself assessed properly to find out whether its a problem arising from your neck and getting referred to your shoulder or is problem of shoulder thats causing dysfunction at neck muscles... for this you need to get yourself assessed thouroughly by a Good MUSCULOSKELETAL physio or Orthopedic surgeon and come to diagnosis.. once diagnosed its not very difficult to treat.
if its the trouble of long duration (more than 2 weeks) then do the HOT WATER FOMENTATION, if its more of a recent injury than do apply ICE,
The pain in shoulder and neck are always related. The way you have described your pain it seems you are having problems in your shoulder joint. f yhe ranges are also effected than it could be frozen shoulder. You should consult a therapist who can assess and plan your treatment. If ignored it can take mony months to heal
Sir, apologies for the delayed response, the problem you have described is very little information to exactly jump on to conclusion of what to suggest you or what not.
certain things that are relevant would be (are you still employed or not ) what are the tasks that you do , and since how long the pain has been , how is your posture, and also what relieves the pain. a thorough assessment is required.
if i assume all the commonest causes and most common scenario for this debilitating condition, it might be frozen shoulder which has progressed and now stiffness in trapezius muscle.
for it manual exercises are to be done by an expert therapist otherwise you may end up injuring your rotator cuff muscles and end up in pain and distress.
seek online consultation else visit the nearest good clinic. for a better understanding of your condition.
DO NOT IGNORE THE PROBLEM > SEEK IMMEDIATE CONSULTATION. from someone specialising . (he / she will not only put you on machines.). Stay healthy