Hyperbole, if used correctly and sparingly, can convey a great depth of emotion. It is the use of exaggeration to make a point, to create emphasis.
People use hyperbole most often in everyday speech. "That bag weighs a ton." "I'm starving." "I died laughing." None of those statements is meant to be taken literally.
Choose your moments carefully, when using hyperbole. It's important for your readers to recognize when to take you at your word, and when you're just making a point.
No Harry Potter references this time. Sorry! I'll work him back in soon, though.