I am 17 years old, I m a girl, 5ft, I am not athletic at all, I weigh about 110 and all of the sudden for the past week or two, I ve been constantly hungry. I can eat a full meal, but then feel like I didn t eat anything at all and be starving an hour or less later. I have also been getting frequent headaches during the day and lately, i cannot sleep well at night. What could be going on