[Coffee.]

As Nicole said, I would talk to your mother. She has no right to treat you this way. You should also see if both you and your mother can start seeing a professional. Your behavior is unhealthy, and surprisingly, your mother's is unhealthy for herself as well, people don't pick on others unless they themselves have something to be insecure about.
Here are some healthy alternatives to Self Harm which can also be handy for purging as well. Reply or message me if you need anything!