Cutting is a sign of depression, cutters are crying out for help, very few ever kill themselves. I have a friend who did this when she was in high school. She told me how she felt and wished that her mom would have gotten her help, but she felt all alone and had no one to turn to. Her life is a horrible mess now. This boy needs help ASAP he is very depressed. Right now his threats to you are frightening but he is not your responsibility. I would advise him to get therapy, or to talk to someone, a teacher perhaps. Then you need to stay away from him till he is mentally well. Perhaps you could tell your mom what you have told us and she can talk to his mom. Cutters hide this, I am sure his mom has NO idea, she just thinks her son is angry all the time. If it was my daughter I would want someone to tell me so I could get her help. She might be mad at first but after she gets help that would all change. Good luck to you this is not an easy place to be. Confide in your mom and trust her, it will be a burdon off your mind.