Thanks for your query.
You need to be worried about your son's health. Basically you have put him on the wrong habit of coke and cold
drink which need to be cut. But more important is to consult your doctor and start the child on hematinics (iron preparation) to build his hemoglobin
. Along with this he will require other vitamin supplements to replenish the nutrients which he has not been having from food. Once things start improving he will start accepting food items too.
This is going to take some time and not happen overnight.
I hope I have answered your query to your satisfaction. Please feel free to revert back for any clarification or if you have anything else to share.
Wishing your son all the best...