Help:Cut my hair too thin...=(

I recently (pre joining this forum) used to have quite thick nice hair. I undertook the task of thinning my hair myself....big mistake...it looked really thin on top, but this i hope was due to the long time I spent most the time cutting away at. I decided this wasnt one and decided to have my hair cut really short but enough left just to style a bit. But my hair still looks really thin. Is there anything I could do to get it back to a thick look again?
 (Ive started taking multi vitamins to make sure I get a healthy amount of vitamins Ive read helps)

Nero

A shorter blunt cut would make your hair look the thickest.