It could be due to cervical spondylosis
this is quite a common condition
rule out diabetes
& vit. D deficiency or any other metabolic disorder.
Sleep on a hard bed with soft bedding on it.
Use no pillow under the head.
Any way take ibuprofen
200mg od & sos x 5days do neck & back (spine) exercises
contact me again if need be.
Use of cervical collar will give you relief.
It may have to be further investigated.
Make sure you are not allergic to any of the medicines you are going to take
you will need other supportive medicines also.