A bully is a person who picks on people. Bullies upset other people. Do you bully yourself? You know, do you tell yourself things like "I'm stupid" or "I can't do anything right" or "No one likes me"?
You need to change that bad habit! Tell yourself nice things. Say, "I am nice to other people. I will be nice to myself, too." Make a list of good things about yourself. Put the list where you can read it to yourself every day. Put it on your bathroom mirror and look at your reflection as you read each item. If you don't want anyone else to see it, keep it in a drawer or inside your closet. But you should read it every day.