I can imagine you are worried about many things at thirteen. First of all do your best to take a deep breath blow it out slowly and do it again a couple more times in times of anxiety. The more a person worries the more scared they become. That happens to ALL people when they feel anxious. If you do indeed have frequent chest pain, it is always a good idea to have your doctor check things out. It is simply a wise thing to do, and it will be one of the things that will help you be able to calm down and stop worrying. Sometimes taking too much over- the- counter medicine such as aspirin or ibuprophen can cause ringing in the ears. When you do exercise, make sure and do warm up exercises first to prevent the strains and pains that come from not doing so. Finally, make a list of all of the things that you personally can do to help yourself relax and relieve your anxiety i.e. listening to music, walking and jogging, watching your favorite show etc. Those things that work BEST for you. If you continue to feel too stressed, seek professional help. My brother did just that years ago and now lives a happy, healthy, professional(he's a graphic artist) panic attack free life. Good luck to you!