I would not assume that your receiving the pamphlet implies that you have chronic obstructive pulmonary disease (COPD); more likely the suggestion that if you continue to smoke you will be at increased risk of developing COPD. You should simply ask your doctor what message was intended. The “changes” on your x-ray attributable to smoking would imply a heightened risk, with the disease perhaps already in progress. That this information has prompted you to quit smoking is a very good thing. You should work with your doctor to optimize your chances of quitting, for good. That could include pharmacologic therapy, such as nicotine replacement and others, attendance at a support group and more education on smoking and its hazards.
Chest x-ray findings suggestive of COPD are not a sensitive way to make the diagnosis of COPD. Pulmonary function tests (PFTs) are the best way. Now that the question of COPD has been raised you should ask your doctor to perform a simple breathing test called spirometry. Both of you will then be better informed about the true state of your lungs.
Statements like “the damage is done” and “gotta die sometime” are miserable excuses and definitely not in your best interest to invoke them. They say nothing about the devastating effect of smoking, resulting in COPD, on your quality of life. Do not buy-in to those arguments.
Good luck.