Sorry to say, there are no cures, but there are good treatments, especially with inhaled medicine. If you have not already stopped smoking cigarettes, you must stop immediately. Then you should begin respiratory medicine for this condition. This would include a long-acting bronchodilator, such as Serevent® Inhalation Aerosol (salmeterol xinafoate), Foradil® Aerolizer™ (formoterol fumarate inhalation powder) or Spiriva® HandiHaler® (tiotropium bromide inhalation powder) along with an inhaled steroid. Another potentially helpful, oral medicine is called theophylline. Your doctor may also want to prescribe this.
You should have your blood oxygen level checked, in case it is low and you would need supplemental oxygen. Arrange to get plenty of exercise, daily. If accessible, you should also ask your doctor to enroll you in a pulmonary rehabilitation program.
If you follow the above, your lungs should continue to serve you well, for a long time.
The diagnosis of COPD actually covers two different diseases, emphysema and/or chronic bronchitis. I don't know of any homeopathic treatments for emphysema, but there are herbal treatments for overall respiratory function that may help. The best book I have ever found on herbal/homeopathic treatments is 'Back to Eden' by Jethro Kloss