I too started early. I became an EMT-A (B other places), the summer between my Jr. and Sr. years in high school. Actually made my first run the day before my 18th birthday, the State gave me the one day. I can honestly say that starting out young may not be the best way for everyone. I look back now and don't know if it was the best way to get started. And like some others have said, EMS is not for everyone that wants to do it. Like a lot of people want to be an astronaut, but they can't. Same as in EMS and/ or Firefighting. I think your location has a lot to do with it, not the best place to start. If you are really determined you may want to think of relocating. But I'm telling you now, lack of sleep, being over-worked and under-paid, exhaustion, adrenaline highs and lows, long hours, it's all part of it. If you don't think you can tolerate these things, then EMS is not for you. And there is no shame in it at all. Just be proud that you became an EMT and attempted a career in it.
Anytime you need to vent or need advice, don't hesitate to post-up.