This is case of cervical trapezius tendinitis.get a help of good physio in your area.you will become alright.regards dr pankaj agrawal shoulder knee reconstruction surgeon Ahmedabad

Hot fomentation x twice daily. Neck Exercises. Neck Stretching. Postural Correction. Shoulder Shrugs . Core Strengthening Exercises. Take frequent Breaks at work Use cervical pillow. Use Back Support. Self Massage the back of neck.

Your case definitely needs a through assessment may be some spondylitic changes have happened that needs to tracked also some disc issues could be there if your symptoms started abruptly there is a common condition now getting predominantly known with more people using tabs and mobiles called as Text Neck. so plz get it assessed!

Using computers n mobiles in excess puts stress on spine bones, you should use it in a limit...if your pain doesn't subside then go for a check up or some physio sessions... Learn posture while using computer n mob...

You have already taken a step towards reducing stress on the neck and shoulder. Since you have the problem from 4 months consult an orthopedic surgeon and get evaluated. Neck problems must be distinguished from shoulder issues as treatment differs.