First of all please inform an adult around you mainly someone in your family I am sure they will listen to you and support you. vent out your feelings, at times our mind gets negative and we r unable to look at the positive aspects of life this is primarily due to a psychological disorder. Trust me like any other medical problem these thoughts which are again symptoms of a maybe disorder will go away with treatment. You have hope an option to seek professional help and get over your problems. I am sure you will feel better. Harming self will lead you no where but if assure you that give treatment a try for a month you will definitely feel better. I also suggest that you need to force yourself to follow a routine, socialize with friends or family. Also Remember like any other medical problem this is just a phase in which you may need some support to feel good again. You can contact me for further queries and also inform your family at the earliest it helps.