Feeling Insecure

In the past few days, as I've started my new position, I've been wondering whether or not I'll be an adequate teacher to my students. I've especially been concerned about what the principal will think of my teaching when he comes to observe me. Then I realized that I've successfully completed my practice placements in teacher's college, I've managed to do a pretty good job "on the fly" as a supply teacher, and surely, with my very own plans, I should be able to help my students accomplish something - hopefully it will be many things. And that's really what matters right? Anyway, I'm often too hard on myself. I can be so patient and encouraging with my students but when it comes to me I take out the red pen and mark X's all over. :p I'm still working on that New Year's resolution--to take it easy and be kind to myself.