So about a month ago, I received an offer to be a long term sub for an 8th grade science teacher. It was my dream job, but now, I'm not so sure. I know that I came in at the fourth marking period and all students are thinking about is graduation. Some of my classes are easier than others and I have one class in particular that it's almost impossible for me to get through a lesson. I'm feeling like a failure because I was so unprepared for this and the principal who hired me has so much faith in me. My student teaching internship wasn't much help either. What can I do to help them stay on task? I'm thinking about changing careers. I don't want to but I don't know what to do anymore. If I'm feeling like this now, I don't think there is hope for me when I get a full-time job.