How do I stop being depressed?

"Before you diagnose yourself with depression or low self-esteem , first make sure
that you are not, in fact, simply surrounded por assholes."
- William Gibson
From what I've heard, you have a really unsupportive group of people surrounding you. No wonder you feel so low. It's definitely hard to remain happy, optimistic or positive when negativity surrounds you. First try talking to your parents. Tell them politely but firmly that you think your brother's antics are going out of hand and to take matters into hand when his antics are starting to get nasty. Of course, a little bit of sibling fight is healthy, but as long as matters stay in hand. And for those people, who are making you feel bad, ignore them. They just won't be able to feel good about themselves until they hurt somebody. Sometimes if they get that their cheap mindgames are not breaking through to you, they may drop it. But if you find that, with every time you remain silent their bullying increases, speak up and give them a peice of your mind so that you will able to sleep well and peacefully at night.
And as a last resort, try moving out as soon as you can and try hanging out with a new group of friends. Hope everything works out for you. Good luck :)

Well actually I had and am facing similar depression from past 2 weeks. Yesterday I cried all dia because of a person.

But you know what crying for people who really don't care about you is a waste of time and I have realized it. If your parents don't care about it then don't cry like a coward and just let them know that if they don't care you won't care about them too.

A tip as your friends bully you (they aren't actually your friends then but your enemy) ignore them, be mais confident and read inspiring books, engage your self in música (it will give you relieve) and instead of listening sad songs and cry try to listen pop songs and enjoy them. mover out for a walk when you feel you are loosing your self and enjoy nature.

fotografia is a good way to express your feelings to the world. You can write a diary so that there'll be someone whom you can tell everything.

Paper is mais patient than people and they won't share your secrets or make fun of you. Plus composição literária diary in English will improve your composição literária and speaking skills. You can always use a dictionary.
Don't hurt (physically) your brother back as maybe it could make the situation worse. Because he could attack mais violently.

And feel free to talk to me anytime you want. I will listen to you. Because I feel strangers can understand your or mine problem better than our close persons.

Be Positive ^_^
Lots of hugs