Sometimes our hormones cause our thinking habits to take a turn for the worse. I have that happen to me. I will be fine and then one little thing sets me off and Watch out! A good night sleep helps to refresh the brain. Just don't dwell on the issue and try to think good thoughts and relax. Watch a funny or good movie and let nature take its course.
People generally get angry when they feel as though they are being taken advantage of or are misunderstood. Try to understand what is bothering you by talking it out with a parent or friend. Once you understand what is making you unhappy, you'll begin to feel better.