Your neck pain has been on an increased curve since 3 years ... as you say you started the problem long back due to long hours of studying ..so definately faulty posture is to blame.... you need to get x-ray of your cervical spine in AP and Lateral view ... if there are degenerative changes and osteophyte formation if seen on xray then cervical spondylysis could be a possibility... also get your serum
calcium level checked.... with modern day lifestyle n working pattern along with faulty posture is to be blamed for a number of musculoskeletal problems... also you mentioned the pain in your face bilaterally this could be worrisome as most of the neck pain of spondylysis patients dont give a typical history of face pain...i had treated patients with face pain but they were cases of trigeminal neuralgia... for the time being i suggest you to have your cervical xrays and sr calcium level checked.
Do resort back to me with any furthur queries.
Have a good day.