I agree with LDR, and I also think that 19 is very young to be criticizing yourself for having no direction in life. Don't be so hard on yourself!
If you're really a manager (and the job sounded very administrative to me, from what you've said of your duties, with you reporting to your own managers), then ask yourself what kind of company would hire a 19-year-old manager with no experience? Possibly so that they can have someone in place that they can push around a bit? What I'm trying to say is that a lot of companies will give you a title, but then not give you any resources to do that title justice, and you end up not really having a clue where your responsibilities start and end. If you're the office administrator, then you know where you are. If you're a manager, then others should be doing the basic admin and you should be supervising them....
I dunno what to suggest, I stayed in a job I hated for MANY years because I had a mortgage from the age of 19 and it had to be paid, but miraculously through working my way up a bit things became much more interesting and I actually ended up in a pretty interesting job, but that took several years, not sure if that's what you want.
If I could do the time machine thing, at your age I would certainly get back into education. You CAN stick with education if you choose to, the majority of people are no better motivated than you, they just force themselves to get on with it.