Flat Ironed Hair Limp and Lifeless

Hi I'm new to this forum.  I decided to join this forum becuase I noticed that it seems to be really active to responses to problems posted every few days. 

But now onto my question....  I'm a guy and I'm a mix between my irish dad who has really fine hair that seems to be able to easily take on any kind of style (Wavey or Straight) and my chinese mom who has fine bone straight hair.  My hair in contrast is a bit coarse and thick.  Its quite strain at the top and back of my head, but becomes more curly at the front and at the ends of the hair on the back of my head(you know what I mean?).

well I dislike my wavey hair so I flat iron it.  When it was shorter this seemed to work fine, but now that its grown out to about 3.5 inches, i noticed that it seems to be limp and lifeless and jst flops onto my forehead.  I use wax to give my hair roots some lift and this works at first, but as the day goes on my hair seems to want to droop down.  I want to style my hair so that it is shorter at the top, sides, and back, but with really long bangs that I can sweep down over my face.

I was wondering if anyone knows how to give the roots of my bangs a little lift so that they don't stick flat to my forehead but stick out a little?  Any advice is appreciated.  I'll try to post a picture tomorrow to show you what I mean.

ever sprayed your roots with volumizing hairspray?

or blow dry your hair upside down before you straighten...

OR both?

on my bro's hair, i actually straighten his hair from behind, so his bangs kind of resist falling completely flat over his forehead...

The wax may be too heavy for your hair.