Join the explorers and don't quit. Eat right, get in shape. And not just in shape, but IN SHAPE. Your body becomes the most important thing when being a firemen. You need it to be ready for anything, and it can't fail on you, or-else you can get yourself, or other people seriously injured. If your not in shape you are only setting yourself up for failure. Stress is in the job, days when you'll be cool and relaxed, but stress builds and that can be a problem. Get your mind right, and be professional and be a leader. in the explorers you find out out bad you really want to be a firemen. If you want it bad enough, you'll become one. No need to get worked up about it, just stay relaxed, and work through each problem one at a time. In training they will try to get you worked up, in a panic etc etc. don't listen to them. you know what you have to do, and you know how to do it, so just follow through. There will be nights/days when you want to sleep, but your going to have to set that aside and push through and study.
Heres a vid that got me through most/ if not all hard times I've ever had with getting EMT/FF certs.
Any questions feel free to Pm on here. If you want to talk in TS3 PM a time and we'll get something going.