I'm not even kidding right now.
You have NO idea how important it is that if you're feeling sad, angry or depressed that you tell someone. DONT keep bottled up. Thats NOT going to solve anything. It isnt going to make anything better.  And i'm not talking about going to see a professional like every week, but just talk to somebody every now and again and when you're feeling sad.
Trust me, you have NO idea how much it helps.
But talk to someone you trust a lot. Your best bet will be somebody who knows what your going through, is going through the same thing or something similar, or a sympathetic person.
Talk to your Mom, Dad, Brother, Sister, A teacher you really trust, Your bestfriend, Grandma, ANYBODY you trust.
It will be the best thing that you've ever decided to do. It will make you feel like you've been saved. It feels like all your troubles have gotten even the slighest bit better. But please, witty girls, PROMISE me you'll talk to somebody? And don't worry, i'm here for you all too.
Trust me, please, because it will do you a world of good.