Excited but scared

Hi! My name is Linnea. I go to a music school and that means that I have music 5 times every week. So this week we are having Christmas concerts. We don't have any ordinary classes for the entire week. That may sound like a dream for some people but it's like the opposite. I suffer from anxiety and panic attacks, today was the first day of rehearsals. It started of pretty good but after lunch it went down the hill. And at the end of the day Icould barleybreath and I where very close to have a panic attack. Luckily I could save myself andI ran out from the room we were in. But I Can't do that for the entire week, especially not during a concert. Do you have any tips how I can do to not pass out or have panicattacks every day??