I am a 19 year old female. My height is 5 feet and 6 inches, and my weight is 160. For the past month, I have been experiencing weight loss, increased hunger, increased thirst, and frequently need to go to the bathroom to pee out large amounts. My skin has become dry. I have also lost quite a bit of weight. I experience moodiness and I am often tired despite a good night's sleep. I brought these up with my doctor but she dismissed my concerns. What could be causing these symptoms?