Midlife Crisis?

I'm eighteen. Actually, not yet. I will be eighteen in ten day though, and I feel like I am having a midlife crisis already, even though I have hardly lived my life; therefore the thought of a midlife crisis seems impossible.
I looked it up, the definition of what a midlife crisis is. Did you know there is a band called Midlife Crisis? Neither did I. Google defines it as: an emotional crisis of identity and self-confidence that can occur in early middle age. I feel like that describes me perfectly. I know, as a young adult it's perfectly normal to have no idea who you are. But I really have no idea who I am. All my friends have gone of to college and university and have some idea of where they want to go or what they want to be. I don't.
Put it this way, if you were to ask me where I saw myself in ten years I wouldn't be able to really give you an answer. Honestly, in ten years all I want to be is happy. That's all I can picture. I can't picture myself sitting behind a desk, or answering phones, or writing articles, or taking pictures. All I can see is me, standing, more like floating in this bright blurry space. There is nothing to give me any hint of where I am, no walls or windows, no defining features, I'm not even standing on solid ground.
Like I said, all my friends are off at post-secondary school studying and partying and having fun, and I'm at home doing nothing. I don't even have a job (although I am working very hard to get one). Did I mention, I'm not going to school? Not yet at least, I'm signed up to go in January.
Now I know I am young, and still have a long full life ahead of me, but I guess what I really want to know is; Is it possible to have a midlife crisis at eighteen... Seventeen?