Initially you should start with Isometric Exercises of Neck.
But that will be of not much help, spondylitis at age 31, seems to be a lifestyle issue or could be something related to your posture at work which requires immediate intervention. Visit an Occupational Therapist advice.
Next Steps
Consult an Occupational Therapist for exercise, right postural and ergonomics advice and activities modification if required. It will solve the root cause of your problem.