Give Indian spices Kadda.. Food :  diet rich in minerals , vitamins, and antioxidants.  Green veg , fruits milk , curd, cottage cheese, dal lentils eggs are quite good . Food has to have enough proteins, calories. And vitamins antioxides and fibŕe. I advise home remedy becuse they are effective tasty and efficacious. It works without any side effects. It build up immunity. Even symptoms are relèived. Along with it I recomnend healthy emotional environment. Never argue, or shout or abuse. It transfers negative energy. It gives babies behaviotr problems like lack of sleep, not taking feeds, vomings or diarrhea.  I feel behavior problems are worst . Never leave a child unattended.  Be in contact with them.All these mesures increases immunity , offers sound sleep. And are happy children. Home remedy is mentioned in almost all cases of cold and cough. Pl consult again with prior appoitment  through practo.

This is mostly viral infection Kindly mention the medications you are giving,so that we can narrow down the cause. You are worrying too much,if it's viral infection it will take some time.