yes, if you can't tell a parent or friends trusted parent, definitely call the cops. it's what an adult would do, and they will help you. don't let anyone hurt you and get away with it. they may hurt someone else.
If someone is hurting you, the best thing you can do is to notify someone who can effectively help you - do this as soon as possible, because nobody should go through torture like this. Do not try to wait this out. It'll (most likely) become worse.
Amaira, if someone is hurting you or somebody you know you need to ask them to stop, now!! You can get help from any adult you trust, teacher, mom or dad of friend, relative, anybody you trust. You should do this before someone gets Hurt.