18 years old, 5 7, weight was 123 and has dropped to 111.6. have been coughing up stringy clear mucus and i have a pain in my neck all the time. my chest gets this pain too about once or twice a day. ive lost a lot of weight. my family says i look unhealthy. ive been trying to eat as many calories as possible but am not gaining weight, only losing more. any ideas on what might be wrong with me? im depressed all the time, i dont take anything for it but i dont think that is causing any of this