Am I reading it right that you’re only sleeping 6 hours a night? That might not be a good idea. Sleep is important to brain development. You may need less than average, but consider that you may be robbing yourself of long-term brain health. At 18 you may not need to control your caloric intake much at all, if you’re eating a healthy diet. You have not posted your SW or GW (or height) which means we as a community can’t provide our collected wisdom. And to boot, we’re just a bunch of internet avatars. Don’t hesitate to ask a medical professional for advice!