I was diagnosed with emphysema a year ago and understand your frustrations. I am at 40% and like you, I'm tired most days but push through. I walk 2 miles a day, go to the gym 3 days a week and play golf once a week. I'm not on O2, just inhalers.
I've learned to live with this disease but also three important things. One, you must stay active and keep moving in whatever form works best for you. Secondly, mindset is everything! I have my days but I try to remind myself of how fortunate I am of what I'm still able to do. I realize this is a progressive disease but my goal is to keep it at bay as long as I can.
The other thing is that you must be your own best healthcare advocate. Ask questions and keep asking questions. If you don't feel your current medication is working or helping tell your physician. Find a pulmonologist that you trust and will actually listen to you. If you have that now, you're in a great place.
This group is a good place to ask questions as well!