Have you tried clipping your roots while your hair is drying? That seems to add root-curl for some folks here. I do this myself to add volume. Get some mid-sized octopus/claw clips, and use them to grab the root hair along your part. The clips should be standing straight up along your part when you are done. Not sure if this will help or not, but it's worth a shot! Hopefully others will chime in with more recs.