Your neck pain looks to be a pain of cervical spondylosis
with compressive rediculo and myelo pathy.
This is a problem usually present in group who constantly work on table, computer, and bad posture.
You require a cervical collar
and some alalgesics like paracetamol
and ibuprofen, and cold packs, SW diathermy to provide instant relief. I feel the use of pillow is required when you are lying on your back, other wise your head falls back and it increases the pain. The height of pillow should be according to your comfort. While lying on side you again require a pillow .little bit more height than the previous one
Consult your doctor , or ortho doctor for further management , and X ray and MRI to evaluate the basics of disease process . You should also plan to look for any systemic and metabolic disease . Take care about Vit D level and osteoporosis
Should also see for any local destructive disease
this is a brief answer