Tamar217 - Don't worry about failing anything. At one point whilst trying to find a way into aviation I thought that ATC was a good way to go until I could afford to fund flight training. However, I failed the ATC entrance exams somehow! Largely down to not really applying myself 100% because it wasn't actually what I wanted to be doing.
Yes I've done some growing up since then but even so I was gutted at the time. But what else could I expect having not worked at it.
My parents were dissapointed with me when I announced that I was boldly binning my current career to go off into a world of uncertainty and hurrendous debt but they got over it when they saw how hard I worked to get where I am now.
Bottom line, don't give up fella. I remember being 18 and all so eager to get onto a training course so I know exactly how you're feeling. Just plug away at it, find and speak to as many different sources of info as possible to get the whole picture. From that you can decide what best for YOU.
That's what I did anyway. Hope this helps!
Chris