Could Racing Heart, Lightheadedness, And Nausea Be Related To Anxiety Or Panic Attacks?

Okay so when I was in my Orchestra class yesterday at school, right before it, I had read an article about Sudden Cardiac Arrest/Death and got a little freaked out about it as I am very paranoid about my health and death. However, I calmed down when class started by my heart didn t. I know that doesn t really make sense, but my heart felt like it was racing and my chest was really uncomfortable. I started feeling a little lightheaded and nauseated and was having trouble focusing on my sheet music and playing my instrument. It got so bad that I asked my teacher to head to the Nurse s office. I was able to walk straight, althout it was a bit shaky at first. I get to the Nurse s office and tell them what s going on and they check my blood pressure and listen to my heart. The nurse said my heart sounded healthy and strong, and that it was no racing, but beating at a normal pace. However, it felt like it was racing and I had to lie down a little bit to feel better. When I got home from school, it happened again, in a lesser amount but it still happened. Before I fell asleep, my heart started beating loudly, or at least that s what it felt like. This morning, less than an hour waking up, my heart felt like it was racing again and I felt a little lightheaded. Just five minutes ago Im getting the same feeling again. I do consider myself an anxious person and I have a lot of anxious thoughts, and I have had a few panic attacks before but they have never made my heart feel this uncomfortable. I don t know if this matters or not, but I m only fifteen (15) and a girl. Should I go to the Nurse s office again? Is there something seriously wrong with my heart? Are these symptoms or something?