I have never dealt with this, but here is my advice:
The world has a purpose and you are part of it. Don't let all the horrible things make you forget about the good. I bet there is more good than you know. If you keep on pushing, in the end, you will not regret it. Things may get better, and if not, you didn't give up. Tell your parents. Most people who have this problem think the same way and it gets worse. You're there child. Not a burden. Trust me.
Just tell them.
I suggest you make a list of all the good things everyday and tell your parents.