My daughter had whooping cough as a baby (although she doesn’t have CAH) but I do know what you must be going through.  It is very frightening when they are coughing and wheezing and fighting for breath.  I am surprised Edward is managing to cope without stress dosing but pleased to hear he is on the way to recovery now.  My daughter had a lingering cough for months after but we got through it, even though it was very tiring - I remember too well the sleepless nights!