It is maybe because of sitting for long in an inappropriate posture. If possible you can follow the Pomodoro technique of studying. Where you study for 45 min, and take a 15 min break where you stretch yourself and relax yourself for a while. For the pain you can apply Diclofenac gel locally over the affected region. Sitting properly upright is also an important part. Make sure your spine is straight, use a proper chair and adequate height of the table so that you don't need to lean down your neck much. Thank you for asking. Hope I am able to curb your doubt. Stay healthy. Stay home. Keep studying. :)