> - if you have trouble with nose breathing like me, use Nose strips (that helps for me)

Just to clarify your intent there: do mean you _must_ breathe through your nose or that you _must_not_ breathe through your nose? (And what on earth is a Nose Strip?)

If this requires mouth-breathing, it's a non-starter for me :(. (Radiation treatment deleted many of my salivary glands, so my mouth dries out, to a painful degree, very quickly, when breathing through my pie hole.)

Nose strips are springy things which hold your nostrils / nasal passages a bit further open. In context, it appears GP means that nose breathing is expected. Sorry about your medical issue; I hope you had a good result.