In any female patient who is in the age range of menstruation
must be ruled out. Once we have a negative pregnancy test we think about viruses, as your symptoms sound viral in nature. Acute Mononucleosis
could produce your symptoms and that has to be tested for. It's generally a self limited illness but it can give you the prolonged fatigue
you describe. You should consult your doctor, it's important to know what the diagnosis is.