Just dropping by again..

So my drawing class is coming around in a few minutes and I really don't want to go. I cannot stand doing these drawings anymore.. Last Wednesday we started drawing something new, it was a cabinet with a bunch of drawers. It took me forever to get done, literally almost the entire class period. So I'm almost done just fixing some minor details and my teacher walks up and says "Why does your cabinet look so narrow?" I almost started crying right there. It was some stupid little mistake that I was even told about before I started the project and I guess when I got into the drawing I completely overlooked that mistake. I guess I wasn't paying attention to what I was doing and just screwed everything up. Now I have to go back into this class and start all over because I can't stand looking at the one I messed up. It drives me insane to dwell on my mistakes, when it comes to my art at least.. If it doesn't turn out the exact way I want it to or how it is supposed to look, I freak out. I have to start all over because it just drives me crazy to look at where I messed up at..