You may be eating too much Protein to compound your problems.
Your digestive system is in a Sick state of affairs, some caused by the Antibiotics and the other by your Diet.
Your Acid Alkaline pH Balance is way out of wack, and as you know you are suffering!!
So you have several choices to make!!
You may continue as you are and get worse!
You may listen to everyone and stay confused as you are now!
Or you may start listening to your own body and to how it reactes to what you are eating!!
If you start listening to your body and get some pH tape and check your urine and saliva first thing each morn, and when you start connecting the dots between what you are eating and what CAUSES you to become too Acidic, and then STOP eating those things, then there is HOPE for you!!
Your child's problem of cracked lips, is just because the body is way too Acidic!
I have made many posts on this very subject, which you may review by clicking on my posts, if you so desire to look.