First, what you describe as “recurrent bronchitis, may actually be a flare-up of asthma.
By standard criteria, a 5-6 mm nodule is a very small nodule and, as you suggest might not be apparent on a chest X-ray. Or, with serial X-rays, might be apparent some of the time and not visible other times. Nevertheless, the first step should be to retrieve all your previous chest X-rays (not just the reports, but the X-rays too) and have them compared with the most recent film that shows the nodule. If you do not smoke cigarettes and are 40-45 years old or less, the recommendation to repeat the CT in six months is sound.
Cryptococcal infection is uncommon. The majority of infections occurs in persons who have one of a number of immunodeficiency states but 20% of infections occur in persons with no underlying disease and these infections are often secondary to exposure to infected pigeon droppings. That you have had no recurrence of this or any other unusual infection in 7 years suggests that you fall in that 20%. Dormancy, with reactivation is almost never a problem.
And, yes, the nodule could be a scar, either from the Cryptococcus or any of a variety of other fungal and/or occupational exposures. It is very common for such scar/nodules to not disappear after an acute infection; to remain in the lung, unchanged in size, indefinitely. Stability of such a nodule over a two year period is considered strong evidence of its being benign.
Yes, it would be safe to take Advair, for either bronchitis or asthma.
Thank you for your time and thoroughness in your answer. I am a smoker @ 25 pack years and am 46. They tested me for HIV - negative but I do have ANA positive. I was exposed to old bird droppings when first moving into my home. Plus I had an MRSA abscess in armpit that took 3 months to clear up last year, but that I believe is unrelated. I really appreciate your answer and will attempt to obtain the old x-rays and have them sent to my current doctor who found the nodule. You have helped relieve some anxiety for me and I am grateful.