From the description, I think COPD might be what my paternal grandfather died from. He smoked very heavily and it destroyed his body. He had to get wheeled around while permanently attached to an oxygen tank. Eventually he ended up in the hospital, where he lived... sorry that's not a good description, "lingered" in great pain, trying to breathe, until he finally succumbed. Along the way the family savings were wiped out to help pay for medical bills. All utterly preventable.
Even complete tobacco addicts like my grandfather can quit; I know because after he was given the "you're going to die soon" diagnosis, he completely gave up smoking. If only he would have quit earlier...
For the last couple of months my Mom was on 10 liters of O2 per min. That is not a typo. 10. Most people you see out and about on small Helios type systems are on 2-4 liters per min. 10 still wasnt enough. Her sats would drop with activity and when I say activity I mean getting up off the chair and walking across the room. Also when you are on that high of a liter flow you touch on the area of CO2 retention, which Im quite sure was the case for my Mom. You can Google it but CO2 retention = not good.
Stick to it Deathy. Stay off the cigs.