Why is this person bullying me?

Someone I know is a narcissistic bully who is emotionally abusing me. They tattle on me every time I call them out. They have threatened to call the police on me and have spread lies that I’m hacking them (I have no clue how to hack computers) and that I sent their friends death threats (I don’t even know who their friends are). I don’t know why they hate me and I don’t want to go to jail. Can you help me?