Teaching practice

After so many positive posts about teaching practice, I guess, it's time for a negative one: mine.
My attitude toward teaching when submitting my documents to TTC was not negative, in fact, now it isn't negative either. I think that the profession of a teacher can be very satisfying. I just couldn't imagine myself as a teacher, as a good teacher. I never thought I was predisposed to become a good teacher, and guess what? After my first ten lessons, is it because of the power of subconscious or something else, it seems I was right. Well, my worst problem, as a matter of fact, the one I was most afraid of, was discipline. The funniest thing is the fact that I am after my practice in primary school. What is it going to be like in junior high school then?
Furthermore, I was never satisfied with my preparation for the lessons. There was always not enough time. I'm afraid that work, practice and studies is too much for me. How can you conduct a good lesson if you're sleepy, tired and so you lack energy and enthusiasm. I don't know how people manage to combine all three. I'm aware of the fact that later it's not going to be any easier; there will always be something that will require to be combined.