A few years ago I became obsessed with my breathing. Mainly, I felt that 99% of the time I could not properly fill my lungs with air. This went on for months. I went to a doctor. He was very impatient with me, basically told me to go home and meditate! I practically begged him for an asthma inhaler because I felt like I was suffocating.
I even stopped consuming caffeine!
A couple of things:
1. It was summer, and VERY humid. Imagine breathing in a steam room
2. My boyfriend had appendicitis and I was worried about him
3. If I distracted myself by watching movies or whatever, I didn't notice the breathing anymore.
Eventually I went back to normal