Sitting in a chair for long hours especially in front of a system with out maintaining proper posture will induce excess strain on the neck as well as on the back. Sitting straight with proper back support is very important. Take frequent breaks in between.
It's very difficult to give any suggestions with out detailed information, but there may be chance of cervical spondylosis. You need to take care of your neck by postural correction. Use proper pillow. Avoid forward Bending For long time. Move your neck side to side -up down 8-10 rept. Twice a day. Apply hot fomentation. Continue for 7 days. If you need any more consultation you may contact me. Thank you.