Sick again!!

Haiiii, xinyi is sick again this few days. Same old problem, running nose, slight cough and the worse. RASHES. She got rashes again all over her face, body, hands and legs. What have i done wrong? I thought i'm a good mother that take good care of my daughter. Why is she keep on sick, getting rashes over and over again. It's really pity seeing her keep on scatching herself because of the itchiness from the rashes. And it's really sad seeing all the red spot on her body. As a mother, what can i do? I've been bring her to see two ped but none of them can really point out what's wrong. except one keep on telling me to switch to soya milk and another one just keep on asking me to control my diet. I'm almost going crazy. Pls help !!