Julie is 42 years old and has had some blood tests to investigate feeling tired all the time. She has been very stressed at work and has attributed her tiredness to this. However, despite a lengthy period of annual leave she remains very fatigued. She denies any abdominal pain, bloating, jaundice or change in bowel habit, but admits sometimes she has a dry mouth and dry eyes. She thinks her weight is stable. Past medical history includes recurrent urinary tract infections and Coeliac disease.
Based on the history alone, what is her most likely diagnosis?