Consistent pain in neck. Serious?

Hi, I woke up one day with sore neck (mostly caused by wrong posture). Pain was really bad and I couldn't move my head at all but it eased away significantly in 2 days and I got on with my daily life. The problem even after ~7 months since that day is it has still not gone completely and I always feel a tinge of pain when I try to move my neck diagonally sideways. Its primarily in the back side of my neck and almost at the lower end of the backside of my head. I also hear cracking sounds when i try to do a movement exercise (rotating my head  clockwise and anticlockwise) Could be something serious? I am a management consultant and spend almost 7-8 hours daily infront of my laptop. Occasionally play badminton and go to the gym 3-4 times a week(mostly only cardio).