Getting into EMS will change your life. I guarantee it. If you do 9-1-1 work, you will see the worst things you will ever see. You will see stark tragedy, people grieving in hysteria, human destruction and things that are just plain gut-wrenching. You will have to explain to parents that their child is dead and there is nothing you can do about it.
These things do not happen all the time. Most of your calls won't be wrapped in so much drama. How you'll react is something you can't know until you experience these types of things. You may cry, vomit, withdraw, panic... Everyone reacts differently. Don't get worked up at this point in your development. Sounds like you have a pretty good state of mind, so take this process one step at a time and hopefully you'll enjoy the experience of your own development.