I'm having neck pain what might be wrong?

Could be several : There can be cervical or neck issues that can cause pain in that area such as disc, muscle or joint issues as well as ear or mastoid problems. Problems related to the occipital nerves which are there can cause pain. Tmj issues can cause pain there as well as vascular problems. Tension can cause pain there as well. Infections from head ; neck region can present as neck pain get it evaluated.

Neck arthritis: There are several joints and intervertebral discs in the neck. These can wear out over time leading to pain. Degeneration of the joints or discs can cause neck pain, headaches, and/or shoulder pain. This can also lead to muscle spasm which limits range of motion in the neck. See your physician if these symptoms don't improve in 1-2 weeks or sooner if you also have headaches and/or fever.