My guess is emphysema

I'm curious as to how your pulmonologist interpreted these findings. My interpretation would be severe COPD. COPD is an umbrella term that includes both chronic bronchitis and emphysema. The test results show evidence of both: borderline response to bronchodilator shows little asthmatic response indicating chronic bronchitis and the air-trapping and decrease in diffusion indicate emphysema. My guess is that your spirometry revealed an FEV1 below 50, and probably somewhere in the 35-40% range.

Your pulmonologist should prescribe meds for you, usually including a long acting beta agonist and a long acting muscarinic agent; both are bronchodilators that work on different cells in the bronchial tubes. That will help with symptoms of being short of breath (sob). You might also be prescribed an inhaled corticosteroid. You should discuss pulmonary rehab with your pulmonologist and if referred take advantage of the program. If that doesn't work for you, talk about establishing a daily exercise program you can do at home. Diet and nutrition are also important.

Disclaimer: EVERY Body IS different!
That said, your results seemingly describe moderate to severe stages of Emphysema. If your symptoms are without excessive coughing and mucus production then Bronchitis is less of a factor for why the lungs do not expel the old gases more efficiently (aka diffusion).
Your doctor should work with you to find the correct balance of diet, medicine, and daily movement (activity) to re-train your breathing patterns, especially those producing stronger air movement upon exhaling.
Meanwhile, the key things you can do is to stay hydrated daily and avoid any respiratory infections (flu, cold, etc) at ALL costs. Be well.

Thanks you for responding..

Sounds like you have a blockage somewhere, and it's causing severe problems, not sure about the rest though. Hope you feel better soon though. Xx