hi...I don't know if this applies in your son's case or not, but I had this problem before, same thing of repeated waking in the night in breathlessness and panic. it'd happen over and over all night. It was completely exhausting, I was so tired, but didn't get restful sleep, and it got to be I was terrified to go to sleep. the panic with it was so bad.
with me, the cause was liver congestion and parasites. liver flushes cured it for me...well, not all the parasites, but cleared my liver enough that this didn't happen anymore.