There’s a whole lot of different takes here already, so I’m just going to plug this very excellent book: Practical Anarchism: A Guide for Daily Life and bounce.

Please do not solicit medical advice from the internet. If you are concerned, go to a minute-clinic or other doc-in-a-box. It’s much cheaper than the ER, and they’ll tell you if there’s anything to worry about.

If you are in a situation where needing to barricade your door to prevent your parent’s entry is a regular occurrence, it is probably time to involve child protective services. You don’t need to give details of your situation to strangers on the internet, but I would highly encourage you to go to a trusted friend or family member’s home and contact the authorities.