AAw hun, I've been depressed before, i felt like everyone hated me, I ran away from home, i locked myself in rooms, i cryed all the time, i hurt myself, i faked ill so i didn't have to go to school...
Basically..tell your parents or mum or dad, or a friend who will be there for you..dont stay on the computer coz that makes it even worse,trust me, maybe read or just take your mind off stuff
go out with friends, take long baths and just think of the happy things in your life x
You need someone there for you so go and tell someone whos older Someone in your school who you trust, we used to have 6 formers there for us oh and yes childline