I would say if this is completely different for you, please get it checked out. Young people can have arrhythmia problems which can cause chest pain. I hope it's not heart related but it would be better to find that out now rather than be worried all the time.
Being tired, being stressed can make your heart beat differently. Try to keep those under control as much as possible.
I think the reason why we get "paranoid" about heart desease (especially heart desease as it is a very important organ!) is when you read about young people - younger or just a little bit older than you - that get heart attacks and heart deseases, etc. we wonder: "why do bad things happen to good people and what if I'm next?"
In my own experience: if you are worried about something then get it checked out. The knowledge that there is nothing wrong will calm you down and make it easier to accept that it is nothing serious and no need to worry.
It can be muscle-issues or it can even be acid reflux! I am sure when you tell your parents about your fears and symptoms they will take you to your Family Physician.
So get yourself checked out by a Doctor and if all the tests and Doctors say that there is nothing physically wrong, then you can work on anxiety and don't be afraid to go and see a Psycologist.
Insomnia and heart palpitations are signs and symptoms of depression and anxiety, but it can also be something in your body/blood that is physically out of sinc.
So get it checked out and be sure.
I have to agree with Jon. Chest pain at your age which is caused by heart disease, is extremely rare even in children born with congenital forms of heart disease. You would be pretty sick at this point if the pain was heart related. Try and get help for your panic attacks, that will help you to calm yourself down and enjoy your teen years.
You are over reacting, your heart is almost certainly fine. If you are concerned, have your parents take you to your doctor to be sure, but it is highly unlikely to have anything to do with your heart. Chest pain from your heart is a constant pressure like pain that radiates to your arm, back and throat. It does not change with movement or breathing or by being touched. Heart pains are not normally "on and off", they do not change. What you describe sounds more like a musculoskeletal issues, meaning with your muscle and bone structures in your chest which is common when you are growing.
Hope this helps,
Jon