Save my hair? Options

[lulumoo]

Alright. So I recently just got a hair cut (sidebangs & layers, with the bottom-most layer ending about an inch down my back and the top-most layer equal to about my shoulders). I thought it looked okay until when brushing my hair, I looked in the mirror today and saw that, from a side-view, it is really very poofy. Kind of surprised since (I'm Asian), and my hair is almost always pin-straight. I figure it was probably the layers, since my hair isn't very thin and possibly doesn't handle the volume well?

So anyway, the sideview, starting from the top of my head down to the longest piece of hair, is basically like the slope of a mountain, and it just looks really...disgusting.

Any suggestions on how to turn it back to the usual straight-Asian-version? I'm considering maybe buying a flat-iron/straightener (is there a difference?), but I'm not really sure that'll fix the problem. If it'd work, any brands you like in particular?

Tell me if the situation isn't clear, and needs a picture. (: