I need help with this, seriously? :(?

Ok so my hair was naturally curly. But now since i flat iron it everyday, its not curly anymore. Its this poofy/straight looking thing. When i try to curl it with moose and stuff, the curls just drop and it looks nasty. What should i do? :/ Is there any other way to curl it without using heat? Or is there some thing i can put on my hair to make my natural curls come back?