Happiness seems like a very big word at times, sometimes it's really easy to put a smile on your face but sometimes turning that frown upside down is the hardest thing in the world. I think that it is important to live a happy life, what is life when you're dreading every day of it. There are so many fun things to live for.
What I like to do when I'm feeling a bit under the weather, I like to first if I really need to, bawl my eyes out, just let out on my emotions.(but not with food ) Then I'll do something that makes feel happy. Sometimes I'll watch a funny movie, if I don't have enough time I'll listen to an upbeat song or watch a funny YouTube video. It doesn't really matter as long as you have fun. However don't do something you'll regret like getting drunk(especially if you're underaged ) eating a whole tub of ice-cream or going shopping and wasting a load of money. This is because when you think back later, you'll ask yourself why did you do that, if you feel really bad about it you'll be unhappy again and the cycle will never end.
After a few days or until you feel one hundred percent good, you'll want to think why where you unhappy but try doing it positively and try to think what can I do to prevent it from occurring again.
If I was annoyed because someone insulted me, I would tell tell myself to not let it get to me next time and just forget about it as there are many more good things about you then bad, and they were just unlucky to be the one to witness your bad side.
Some things in life just aren't worth it, so just try your best to look on the positive side of things and remember that you are beautiful in your own way and no one can put you down. You are stronger than the people that put you down.