It is excellent you quit smoking and you should be scared. COPD is hell. Thank God you are in initial stages. only a pulmonary Doctor can give you the answers you need, but please take him or her seriously. Good luck, I pray you get no worse.

I quit and 4 years later it the worst ever I need a pulmonologist

I have heard that every smoker has some stage of emphysema working on them. Not sure how true that is, but it sounds like you have caught it early. It's great that you have stopped smoking, but not that you were scared into it.
It sounds like you are on a CPAP machine.
Have it checked by a pulmonary doctor.
Best of luck to you and keep us posted.

Exercise is never out of the question unless you're six feet under. I've seen people go to Pulmonary Rehab programs in wheelchairs and walk out under their own power two months later. Talk with your doc about Pulmonary Rehab and if you possibly can, get into a program. Exercise will work for pretty much everyone and will make living a lot easier.

I had a knee replacement in October 2013. I was in the hospital for 11 days. My potassium, sodium, and magnesium got extremely low. I had a blood transfusion and was on oxygen, 10 lpm most of the time. The pulmonologist couldn't figure out why my oxy sats wouldn't stay up. First they thought I had pneumonia, they took X-ray's every day. When I left the hospital I was on 2 lpm with no diagnosis. The pulmonologist I saw when I got out ordered a cat scan, said lungs were clear, and finally said he guessed it was COPD. Now I'm on 4-5 lpm and can do nothing without getting short of breath. I have gained weight from taking the steroids and am puffy. I still work part-time from home, but it's getting harder to get motivated. Needless to say, exercise is out of the question.