Hi Stuart, welcome to this board!
Interesting story (some paragraph splitting spaces might help reading next time

) but a shame to hear it all took so long and didn't work in the end still!
What makes me wonder is, if your machine records 6 hours of decent sleep and you still feel tired, how is your diet in terms of energy uptake? I heard before where people thought their apnea treatment didn't work only to found out they had shocking eating habits. If no decent fuel goes in, no decent power will come out, that sort of idea.