I am 17 years old, no family history of heart problems, in good shape, (145 pounds, 5'9, frequent gym trips, overall good health, vegetarian.) However, over the past three weeks, typically at night, happening almost every night in the past week, I have felt weakness in my chest area, faint, short of breath, slightly odd heart beat (More description later) and a very increased awareness of my heartbeat.

It started three weeks ago, was reading a book, and suddenly felt faint, lightheaded, I got up, stretched a bit, and felt fine about two or three minutes later. No worry in my mind, I didn't know what it was, but, didn't really care.

About a week later, it happened again, at night, sitting down, not moving, (Reading, again) felt similar faintness, weakness in the chest area, checked my pulse and it was high (Resting heart rate of around 60-70, it was about 100 - 110). It lasted only a few minutes and went away.

No concern for a few more days, then, nearly every night, I began to get the same symptoms, however, at this point, I was fairly concerned, wondering what happened the last two times. I had increased awareness of my heartbeat, however, I will admit, it my have been because I was thinking / focusing on my heart.

Recently, it has been a little worse, however, only happening at night time, and the symptoms are not exactly getting worse, more of, just staying the same, once or twice a night, I will feel a bit faint, maybe a little bit of 'weight' on the chest so to speak, sometimes an odd heartbeat.

Now, I do tend to worry, so, I fear I may be causing it myself, by thinking, focusing, and a such, creating the problem, feelings of doom can be of the mind, and worrying can increase heart rate.

I don't see why someone of my age, health, etc, would have heart issues, and from what I know, no heart problems in my family.
No health insurance, so going to a doctor is out of the question, I have never had any other health issues, besides asthma, however, I have since grown out of that, (Ceased when I was around 12-13, now, there are no problems at all with it.)

I am wondering if this could be an actual problem, or if I may have just felt randomly faint, for one reason or another once or twice, and now I am causing it to myself.
Thanks for your time!