Welcome Jessie! We also have a Charlie, so great choice in names
He was born at 28+6 at 1287gms so quite a boofer considering his gestation. Well done little man on getting onto CPAP, it's a HUGE milestone after so many weeks on the vent.
The roller coaster ride is tough, but at 6 weeks in, just keep remembering that he will come home, it doesnt matter if that's on oxygen etc. We have our own premmie mums group including two 24 weekers and a 26 weeker who went home on Oxygen. At over a year out of hospital, they are all doing brilliantly and all walking, talking etc...except for them being smaller than average, you wouldn't know they were micro premmies...
There is light at the end of the tunnel........ from us for the incredibly stressful situation you are in.....