First teaching job

So I am officially a working teacher. Now I graduated in December, thus, I was a teacher but now I am actually about to get paid to be one. It's exciting, scary and really overwhelming all in one breath. This picture says it best. I am barely keeping my head above water and then I turn around and there is another wave of doubt, frustration and anxiety that must be overcome as I proceed down my journey of teaching. I wonder if this is where the term "sink or swim" comes into play?
I know these feelings will pass and it will just take some time to get into a new routine and get comfortable with what I am teaching and how everything operates. Before as an intern at least there was someone in the room with you, now I'm THE teacher...what have I got myself into? It all comes down to change. It's funny, we know nothing stays the same forever and that to grow and evolve we must face change and even seek it out, yet when it gets here we wonder if we will ever experience "normal" again. I think I read somewhere, or someone told me that the feelings of being uncomfortable and uneasy is a sign that we are growing and developing as a person. Well if that is the case, there is a whole lot of growing and developing going on with me right now. I liken it to the analogy of a rock tumbler. You throw the rough, unfinished and raw rock in, it gets tossed around a bit and shaken up and then out comes this lovely unrecognizable piece of wonder. Maybe that is what is happening here. I get thrown into an unfamiliar situation, forced to "sink or swim", and challenged to put to use that which I have been taught and that which I have not. My hope is that I come out the other side, first of all alive, and second a more confident, effective and relaxed teacher and person.
If it was easy, everyone would do it.