Help?

You know that feeling right before a jump scare when your watching a scary movie, or about to go on a big hill on a roller coaster? That’s the best way I can really describe it, at night I feel that *constantly*. I constantly feel like I’m on the edge of going into a panic-sometimes which I do. It makes sleep at night an extremely stressful thing. I can’t see a therapist because I still am a minor and my parents won’t let me. Does anyone have any idea how I can improve this?