The pulse is beating... Isn't it?

Hey, this is my first post.

Im 15 and I am sure, that almost every minute of every day, I have my finger on my pulse. Serious! I have this feeling of impending doom inside that I'm going to have a heart attack, a stroke, cancer, or my heart will stop or something. I've been to the doctors, and i gave blood for tests and everything but nothing was wrong with me. Or so they say. I really don't know. It's been like this for around 4 months now. I'm losing so much sleep over it. Usually having panic attacks twice a day. I can't even go out without fear of collapsing in the street and just having this pain in my heart. The thing is, I think about it so much, that I think im fooling my mind into thinking ive got pain in my heart. I'm not overweight, I've started exercising a lot more than usual. I've started eating better and everything! I've no idea what is wrong with me. If even anything is. But I fear for my life every day. I can't do as many of the things I used to like such as go out with friends or go to parties or anything. I can just, manage to go to the shop near my house. But I think i'm starting to lose friends now. I'm on my computer all of the time because of this. I really really hope that this is all in my head. But I need to get rid of it.

Can anyone help me? Please?

Welcome to HW...I think lyn had given some great advice

Sometimes, with people, teens especially, come to realize (if even subconciously) that today is the first day of the rest of their lives. That's a big thing. Then the personal sabotage can start. The feeling or dread that this rest of your life is going to be cut short with disease or early horrible death--some people wake up the next morining forgetting about these dreads and others keep building on it (or maybe that was just me ). Seems to me you are experiencing some pretty common teenage anxiety (I'm sure docs see this alot and you may have seen this in your doc and may feel like you are not being taken seriously but of course the doc wouldn't tell you that). I don't know what to say to you to help you to relax but do keep busy, go out with your friends--HAVE SOME FUN-You're 15. Talk to your doc about teenage health anxieties and maybe he or she will give you some peace of mind.