Please help me boob issues!?

I'm 11 aNd I have breast buds I dont wear anything under my shirt/top but you can see through it hurts when I knock into something I need a bra but no stupid awnsers like just tell her proper hints like knock one of the rack pick it up and go ooooh that's pretty (I've tried that before!) pls help I'm 12 next month and it's spook embarrassing my best friend (lily) all ready wears one and tells me to get one but I can't tell my mom!!