I'm worried about my hair please help?

I'm a guy my hair touches my collar and covers my eyes and it curls up when it gets over my eyebrows and the back is starting to curl up too! it's not really over my ears all the way but i saw a guy at school with hair like mine and his curled up on the bangs,back and sides and this is what's gonna happen to mine. i'm trying to get it breast length and that's not gonna happen if my hair keeps curling up! my grandparents won't let me get a straightener.What do i do???