I had made up a study of bangs.. let me see if I can find it.
biggrin edit:
here we be

its not perfect .. and its kind of ..
more about hair lines .. but I think that is part of your issue as well.
Your hair line in the center of the face is at its highest point. So this is were the hair from your bangs should split, but not down wards.. but Up and then swings down like shown it is popular in manga to have hair like this. It like an uber cowlick, and having a bit of a major cowlick my self on both sides of my face I know what they look like when they come forward from being combed.. they go up and then swing down. This also gives the characters hair buoyancy.. and volume instead of limp, flat, and dead looking.. when creating hair. try using a series of light strokes also to get a more natural hair look (not required). You can also make the cowlicks smaller in height.. Hair can take a bit to master.