Hello Olivia
This is a common problem and is the result of over processing the relaxer. The purpose of a relaxer is to RELAX the curl, where there is some wave pattern remaining in the hair. Where the relaxer is left on so long that the hair has become STRAIGHTENED rather than relaxed, the hair loses all its body and volume. For now, instead of blow drying your hair when styling, use Dark and Lovely Leave In Stylisng Mist and set your hair on rollers. This will give you more volume and will alst longer than a blow dry. Future relaxers should be left on only until the curl is relaxed, and never taken through to the ends over previously relaxed hair.
Warm regards
Heidi