The steps you suggest change are actually how things happened for me. I think largely because my case turned out to be incredibly serious: blood oxygen falling

The steps you suggest change are actually how things happened for me. I think largely because my case turned out to be incredibly serious: blood oxygen falling below ~80% and breathing ceasing every 45 seconds or so for about a minute each time. That's what happens when you've got Complex Sleep Apnea (combo of obstructive and central).