Oh dear Mr Lee, the continued absence of the stiletto psychopath led me to believe she was up to no good and you have confirmed that, but chin up good will eventually triumph over evil.
Once my oxygen level dropped below 90% I was put on O2 all the time, currently my on air sat. is around 87% but it drops to about 81% if I get a lung infection. With O2 I keep it at about 92%