Is the person who hurts himself mentally ill?
There must be something wrong with his psychology: first, inferiority complex. Then, he may have too much depression in his heart. As a girlfriend, you should pay more attention to him. Then, don't let him feel lonely and nobody cares, and encourage him to have confidence in himself and his life. If you feel that you can't heal his mind, you can also find a professional psychological counselor to help with the work. Please remember that if his self-harm behavior is not stopped, it is difficult to guarantee that he will not do more serious harm in the future. . . .