I hope you've found something that works for you, but I think it's misdirected to be angry at others for not following your direct path. You have no idea if you've found a universal solution (unlikely with the range of symptoms and treatments), or just something that hopefully works for you.
Personally I have seen one of the best pulmonologists in a major US city and haven't found any oxygen issues with blood work, PFT, etc. That's not to say it couldn't still exist and just have been missed, but I suffer from many chronic health problems so nothing is simple. (This is normal for anyone with complex chronic illness, so it's not a big deal.)
Good luck.