Hello dear, You are very young. your pain is mainly postural and due to sustained postures. You need to do neck strengthening exercises,trapezius stretch,levator stretch and improve posture

Hey dear, You're just 19, okay let me tell you something,  this pain could be due to many reasons such as improper way of lifting your backpack,  sitting long hours studying with no breaks in between,  or even too much of stress , lack of proper sleep and nutrition,  handling phone or reading book while sleeping and many more. So what you need to keep in mind is 1st its ok to have a sore neck n back at this young age, 2nd thing you can manage it on your own after getting a proper guidance at first, 3rd it will not horrify u for lifetime... I hope this helps you, Thanks

No avoid exercise do hot fermentation twice a day  and visit physiotherapy centre for proper diagnosis and

Never  do exercise  in severe pain try to sleep  with  out pillow   check  the CBC  in blood test

It might be due to Muscle Tightness or weakness

Consult near by Physiotherapy clinic Need proper assessment by Physiotherapist UST, tens, MFR, and  stretching exercises

Hey, I would advise before taking any treatment you should consult with a good physiotherapist near you so that he/she can assess your problem and treat you accordingly

MFR, Tens, US,  and isometric exercises