How Can Spinal Curvature Be Treated?

Hi i'm alisha from lahore.i am 19yrz old with a weight of 50pounds and height almost 5.8inches. my backbone has bent till from childhood.it luks like in a curve shape.bt when i make my back tight,it becums straight.its also geting weak frm back and its both sides.bt i cant make my back straight for long time,it gets pain.so what could b the cure with suitable diet?