Dear jfijerf, I understand your concern let s figure out the options. Being skinny doesn t means that you ll be healthy. A healthy body status is assessed by Body Mass Index(BMI). Your body mass index, which is based on your height and weight is 17.37 which falls to the category underweight. You should understand that low body mass can decrease your body s immune system, which could lead to illness such as disappearance of periods (women), bone loss, malnutrition and other conditions. You can t be energetic and healthy being underweight. You feel tired because of this. If you try to loose weight any further that will lead to severe electrolyte imbalance in your body which is a very serious condition. With the height you have mentioned normal weight is 120 pounds. Now let s move to the next step. As you are very keen on losing weight further, we need a serious evaluation on the matter. 1. Consult your physician and undergo certain tests to determine whether you have any electrolyte imbalances and if so, we have to correct it first. 2. Your serious concern about being fat, may be due to an eating disorder named Anorexia Nervosa, and your psychiatrist will be able to help you on that matter. Always think, being healthy is far more important than being thin. 3. Avoid taking lot of caffeine as it will further deteriorate your health. Thank you.