What do you like to do to cope with it?
Biphasic sleep? I'd never heard of that! That sounds interesting. Do you have experience with this, Simon Dog, and if so, does it help?
One thing I know for sure is that when people lack oxygen, they are just plain tired and exhausted. I don't know what your stats are running these days (not my business either) but I think anyone would expect you to feel more than a little exhausted. This whole situation makes me sad not that you came here for stranger pity.