Possibly. It could get worse with time, even though you quit smoking a while back. It is important to take your medications such as inhalers, as directed by your doctor in order to prevent further problems.
See below. Everybody's lung function gets worse as we get older. The best thing you did is quit smoking. Make sure you follow up with your doctor and take the necessary medicines to do the best to preserve your lung function.
Yes. Emphysema is a progressive disease. How fast is progressive - depends on you. Smoking is a big part but not only one. Do not forget about second hand smoking. Also exposure to biofuels ( wood burning ), dusts found in coal mining, gold mining, and the cotton textile industry and chemicals such as cadmium, isocyanates, and fumes from welding, genetic factors and many more - stop the exposure.