Avoid using pillow, if u want to -use cervical pillow
Avoid neck exercises in pain,instead take rest
U should see an ortho surgeon and get your x ray done.it seems you have cervical disc problem from your complaints,which is compression of nerve supplying your arm at neck
Next Steps
take rest
take hot fomentation
see ortho surgeon
Health Tips
avoid bending,lifting heavy weight,sleeping with pillow,seeing TV/Reading while lying on bed or sofa