With a ratio of 53% and an FEV1 of 1.7 liters your prognosis for a long life is very good, as long as you do NOT resume smoking. Chronic bronchitis is a cough with mucus that lasts for at least 3 months in a row 2 years in a row. Emphysema is a decrease in airflow and destruction of the airsacs in the lung. Chronic obstructive pulmonary disease (COPD) is a combination of chronic bronchitis and emphysema. As for the normal chest x-ray and CT scan, there is not always a good correlation with the degree of obstruction to air flow and the amount of COPD. Your obesity could also interfere with the imaging of your lungs and COPD. Please continue with your diet and riding your exercise bike daily to lessen your shortness of breath.
Obesity aside, you appear to have enough lung function to live for a lot of years.
I'm not a dr but I was under the impression that COPD is emphysema or chronic broncitis both of which would be seen on a CT scan. If there is nothing seen on film perhaps it is something made worse by your weight?
I have COPD and when I am heavier it is definitely harder to breathe. I struggle with my weight as well.
Perhaps what you need is to see a dr who can prescribe something for anxiety/depression and then the idea of losing weight and excersing will not be so daunting. COPD takes a lonfg time to "get you", you could be in a completely different (better place) by then
linda