Curly hair going straight? please help me!?

ok,so about 6 months ago i had my hair in a bob and i had to straighten it everyday because it looked awful and puffy,now my hair is a a bit below shoulder length,my hair before the cut was ringlets but now its drying pretty much straight but not proper straight. how can i get my curls back? im really sad why has this happened and how can i fix it? xxx