I keep having the same type of nightmares. What does this mean? How do I make it stop?

I keep dreaming about school, I know, it's lame. I'm 12 years-old and going into 7th grade. I'd either be late for school, or forget my homework, or not even get my schedule for my cl. I don't know why I dream about this. I know that none of that is going to happen, I'm responsible enough to avoid those problems. I'm taking all "Pre-AP" cles, including the gifted/talented cl that counts for Reading and English. I'm also taking Spanish as an elective for high school credits, which I've been told is like adding another core-cl onto your schedule. I'm also in athletics, and signed up to try out for the volleyball and basketball team, and outside of school I'm a pitcher in softball. Do I have to much on my schedule? Is that why I keep having this dream? Sometimes the dream will stress me out so much I'll just turn over and sob into my pillow. How can I get the dreams to stop?