It's totally not abnormal for someone young like you to be afraid of death. You know most people don't fear death itself but what comes after it. So what you should do is calm down and understand why you fear it. And then try not to think about it that much. Occupy yourself with something like exercising, reading, or hanging out with friends. And don't just read Quran and pray just out of fear but understand why it's good for you do those things. Ask for somebody's, like family, opinion or perspective, that can help very much you know.
I hope this helps you inshallah