hair flipping on the sides-help!

okay, i am literally a newbie beyond newbies here, so give me a break if i dont know what i'm doing or saying lol.

okay, for the past year i've let my hair grow out, here is me freshmen year:


now, this is a couple pics of me about 8 months later:







okay, anyway, i've gotten several hair trims in the past few months, and my hair that used to be pretty thick, now is pretty thin, and its almost impossible to make it flip out and under on the sides.

my technique i use is using hair bands, and putting 3 around my head, use the blow dryer and use my hands and flip it under, and use hairspray to make it stay.

but its REALLY nappy and it usually never stays, and i have horrible hair days now.

i'm considering cutting it all off and starting over, because i have NO IDEA how to make it thick like i used to have it in those pics.

does anyone have any ideas on how to make it sorta flip out and under? does anyone know what i'm even talking about lol?? im sorry this is long, but im pretty obsessive with my hair, i apologize.

thanks a lot in advanced if u help, *or offer any new hair style suggestions??*