There's something wrong with my bike HELP!!?

[Efren]

So i was riding my bike and while i was riding it i noticed my bike pedal was wiggleing, so i went back home and took it off and when i looked in the crank there was a bunch of metal dust so i blew it out of the crank hole and when i try to screw the pedal back on it wont go all the way in and still wiggles, please tell me what wrong and how much it will cost D;