Career Anxiety

I think I have found out what my problem is when it comes to choosing a career. When I was young, I always loved the fact that I could be anything I wanted to be. Now, that is exactly my problem. There are too many options. It makes me want to consider having children in different countries just so that they have fewer opportunities than I have.
I know that there are some things that I could never do. I can't be a neural surgeon, or an astrophysicist, or anything along those lines. However, there are no careers that I can actually rule out, because I simply haven't found my passion. When I was talking to my sister yesterday, I told her that I'd like to be a director because you can make your own plan. It's not like a boring office job where you come in every day for a set amount of time, but it's not like being an artist, where you can decide whether you do it or not. People expect things of you and give you praise when you do them right.
I had a job over the summer. I lasted a week. One of the things I hated about this job was that there were so many things you had to do but you never knew what they were or how to do them properly. I suppose this might have been because I was new and hadn't learned all of the ropes yet, but I could never get used to that kind of anxiety. If I were the director, I would know what to do and tell people what they had to do because I would be in charge. Even if I had no idea what I was doing, I could learn on the job without terrible consequences.
I may be romanticizing this idea, but it's one of the only careers that I've given serious thought. The only problem is that I have very little experience actually directing.
A lot of the people I've spoken to say that you don't need to know exactly what you're going to do with your life, especially in high school. The problem is, I'm the kind of person that likes to know what to expect. I can't shake the feeling that I'll screw up if I don't have some kind of plan, if I don't have some kind of stability. I'm not opposed to going with the flow; in fact, I enjoy it. But I can't survive without having something concrete to look forward to.