Need help putting lung issues in perspective

[SkaterDave]

I'm a former heavy marijuana smoker (all day every day for 10 years) and light cigarette smoker (half a pack a day for 10 years). In 2006 at 33,i was diagnosed with minimal COPD. In the last few years, a pulmonologist has downgraded that to no COPD but impaired function not rising to the level of COPD. I can swim, ride bike, walk up stairs all with no issues. The problem is that I can feel the damage in my left lung this whole time, and I have fought a losing battle with fear this whole time. My lungs are impaired about 20-25% depending on what aspect is measured so it is real even if not life threatening. My numbers have only dropped in the lay 10 years due to aging my pulmonologist says. I guess I'm posting here for advice on how to handle this Neverending pervasive fear I have of it progressing or getting cancer. If I swim or have sex too vigorously, the wheezing is quite bad, and I feel a black hole in my left lung where air doesn't seem to enter. I've never been able to discern where reality ends and fear begins. If anyone has insights or whatever, please, chip in!

[CHIN_C]

You should stop smoking if you have not done so already.

[SkaterDave]

I shouldn't say I can swim and ask that with no issues it's minimal issues I'd say. My biggest issue is the feeling of deadness in my left lung. The right side feels fine, but the left middle feels like spray foam is in there preventing air from entering. I certainly do get out of breath exerting and the wheezing is pretty bad. It's just enough to make me feel unhealthy, depressed and scared. Any advice, opinions or whatever are invited. Thank you.

[SkaterDave]

I shouldn't say I can swim and ask that with no issues it's minimal issues I'd say. My biggest issue is the feeling of deadness in my left lung. The right side feels fine, but the left middle feels like spray foam is in there preventing air from entering. I certainly do get out of breath exerting and the wheezing is pretty bad. It's just enough to make me feel unhealthy, depressed and scared. Any advice, opinions or whatever are invited. Thank you.