You are feeling tired because of overwork and anxiety, but you are concerned that it is some type of chronic disease. Because of people's fear of a serious diagnosis they don't see their doctor, hoping the symptoms will go away. But they continue to worry about their health. Ultimately, the majority of times, they have no serious problem and this reinforces their reluctance to see their physician. Unfortunately, this reluctance may extend to not seeing their doctors even for routine physical examinations thus missing the opportunity to practice preventative medicine.
Prevention remains the key to good health.