First you might have over conditioned it and what ever product you are using is weighing your hair down. Use 1/4 cup baking soda and wash your hair with it. Rinse throughly. This will strip anything on your hair even hairspray or gel products that simply shampooing will not get rid of. Now wash and condition your hair with a product made for volume. Try and find a good brand from a solon.
I like the thermasilk line and my hair only does one thing naturally well -- straight. I've been accused of using a straightening iron when I don't even have to own one, so anything that allows me to curl my hair and it actually stay stands out, but it will make your hair feel like straw.