NaturalMom, I see your nurse and raise you two nurses, an epidemiologist, a hospital architect, and two physicians (neither of whom, admittedly, are virologists), all of whom have confirmed that the masks are primarily useful to prevent infecting others if you’re already sick.
I realize that you don’t know these people, or me, either, and you are of course free to do as you like. I just hope that includes washing your hands frequently, and want to point out that while wearing masks is also recommended for medical personnel, that’s because they’re presumed to be working with infected people.