This is a really silly question but im scared of life?

i've been depressed about this for a while, im really scared about my future, im 15 and petrified that my life wont work out well :/ loads of people end up doing really bad and living off benefits and i dont want that to happen to me, i have alot of dreams i want to persue and im afraid i wont acheive them, im just really scared about growing up :( i hate it and wish i could be a young child again with no problems, what shall i do? x