Sir,
First we need to assess if the pain is coming from the neck or the shoulder.after which necessary steps to curb the pain can be taken.
Next Steps
consult a physiotherapist. a few sessions of physiotherapist will definitely help you.Along with some postural correction exercises and strengthening exercises for the same.
Health Tips
do not lift anything heavy. if u have sedentary job please do not continuously sit for long time, after about 15 -20 mins just get up and move about do some stretches and again sit back for work.