I have read your comment on COPD, very interesting it sounded identical to my symptoms only difference I have been diagnosed with Emphasema just 6 months ago. I have Asthma, Bronchitis, and COPD for the last two years (that were know about). I need sleeping tabs or I just don’t sleep! What is O2, I’ve never heard of it but you have peaked my interest. Not sure where you live but I’m in Australia.