You have not described the pattern and onset of the pain. If it occurred sudden onset at morning it may be due to malposition while sleeping. It may be due to exacerbation of cervical spondylosis. In that case a radiating pain is observed. Again there is a chance of musculoskeletal pain after some injury. You are on muscle relaxant and analgesic therapy which generally helps to cure the musculoskeletal and arthritic pain. Topical diclofenac gel application along with hot compression or ultrasound therapy or short wave diathermy may improve your symptoms. Physiotherapy also have role. You are also recommended to check your serum glucose and uric acid level as these will help in diagnosis.