Difficulty in breathing & Chest tightnes

I am facing difficulty in complete inhaling. Although I don't feel any tiredness or gasping feeling while doing household chores, exercising, also I am able to do Zumba activity quite comfortably. This has not been a constant condition. I feel ok for 2-3 days..then again I start feeling shortness of breath after a gap of few days. I have been facing this condition from last 10-12 days. I consulted a family Dr. He said this might be due to anxiety. Also my blood oxygen levels are always above 95%. Also I am having a little sticky cough developed internally earlier in the last month. But I am not coughing or having runny nose neither fever. Today I again experienced inability to breathe completely along with a little chest pressure prominently on the right side. I am able to have decent sleep every night once I fall asleep and usually don't wake up until morning. Kindly help.