Do all of you know that song with 2NE1 where they sing something like "Why did it have to rain tonight of all nights? How pathetic dont I look then?" ?

Well... I had a homework in english class to write about how weather can be interpreted depending on your mood. So I wrote something about how a girl had gotten dumped and it started raining and she was all like: "Oh no, I will look pathetic like this. Why couldnt the sun shine?"
Wich is like... A total rip off from the 2NE1 song but I was tired as hell and thought that "Hey, it wouldnt matter if I leave it in to my teacher, she wont know anyway!"

But now I got the text back and I got an A+, wich means I acctually have raised my over all grade this year... And all because I cheated... Im feeling so guilty!!!!! Do you guys think I should tell my teacher and face up to the fact that I will only get an B in final grade, or should I just keep quiet?