Pain at base of neck and radiating towards shoulder and arm may be due to Cervical Spondylitis
Wrong sleeping or sitting posture tend to increase the problem.
Please get yourself examined by an Ortopaedician and get a X-Ray or MRI
of your neck done to confirm the diagnosis.
and some neck exercise suitable for this will reduce the symptoms.
Donot use thick pillow as it will increase the symptoms.
If you have furthur queries, I will be ready to help.