I Am 67 Year Old Female . I Never Catch

I am 67 year old female . I never catch a cold --just bronchitis. I have Sjogrens Disease. I have seen one Dr in my family practice who gives me a ride-biopics and one who won't.
This is about day 4. Very chunky green globs (sorry). Would a humidifier help and should I get anti biopics or not