Hello, I’m A Healthy High School Female Student With A

Hello, I’m a healthy high school female student with a few problems in life, but no record of medical problems. Not even allergies. I do talk to therapists from times to times and recently I have been experiencing a few things such as dizziness, nausea, rapid heart beat, chest pain and hard time breathing. It comes when I’m thinking about something’s thats going on and I’m nervous about it. What is going on and what do I do ? Is it dangerous or should I just ignore it ? I feel like I can’t breath sometimes and it has happened twice today.