Last night's dream and quality of my breath

I was dreaming many things mostly not so pleasant as my stomach was bloated and not very comfortable. But some sort of revelation came to me. I was saying to myself: "Little things are not to be worried. When you have calmness in you, every little things falls into its place, according to your calmness". So half awake, I thought, "That's a good advice". I noticed my heartbeat and it was quite fast, so I tried to control it through my breath. Breathing with my diaphragm. It was useful a little bit. Nowadays, I am trying to control and notice my breath to be long and using my diaphragm. I watched a documentary called "Heal" and it was saying "The quality of your breath, is quality of your life". So, I keep that in mind and whenever nervousness sets in, I simply do the diaphragm breathing and instantly I feel less tension in my body.