Thanks WC.
In India more than 80 percent of the doctors I have seen didn't care about me/take my symptoms seriously.

I was reading articles on the internet about breathing difficulties. I have difficulty breathing through the left nostril. I guess my respiratory muscles are not working as they should and that's reducing the amount of oxygen in my blood and increasing the amount of carbon dioxide, which is making me tired. I will call my doctor after a week if the nasal spray doesn't help and tell him about the respiratory muscle weakness.