COPD is a progressive disease, so yes, it's not unusual for people to begin to feel more breathless as time moves on. There are things you can do that will probably help. Doing 30 minutes of exercise daily (aerobic exercise) and strengthening exercises for the upper, lower and core muscle groups is critical. Weight control and diet are equally important, along with healthy life style in general, taking your meds and avoiding getting really sick. Most of those things you can control yourself, so making those changes requires no prescription or treatment plan and you can do them on your own.

While the change you describe may be normal, you can do things to keep yourself stable. My lung function has been pretty much the same since I was first diagnosed in 2000. I do require more supplemental 02, beginning in about 2013, which is relatively normal.