Oh no, you are totally lost in your body as the "I"!
How to Focus consciously?
That is when you are doing that thing, you are totally lost yourself in the thing you're doing, the-thing-you-are-doing and you become one, that is Chan/Zen. This way, your Mind (Citta) is closer to 100% viable. Most of the time our Citta is few % here, few there, few in the past and few the future... If you could have your Citta unattached to anything you are doing but still "alive", that you are Chan/Zen master-the-great! Therefore, breathe is not you, limbs skin not, sensation cold or hot is not you... However if you recognize these, that means your Citta is not 100% together but divided, hence less the your focus. When you are 100% focus, i.e., the Citta is 100% in one thing absorbed, your breathe will cease... but don't worry, you will still be alive, not die, for human doesn't really sustain on oxygen by the breathe passing only through the nostril... medical has more to learn from the wise ancient people.
It's almost impossible for the Citta to focus on one thing 100%, so is not possible to be unattached in anything. Can you stop the mind from thinking, or observing, or aware of the self?
However, after the training of 100% in grasp of the Citta completed, in this time you are raised to the Bodhisattva in quality, not just by the vow, to a certain level (there are roughly 10 grades in the ladder of qualification), than you can focus in many things at the same time yet each focus get 100%; thus you are multi-tasks capable and could have many vijnana-created-bodies (意生身). By that time, you could have many Ritesh(s), one is doing the coding, one training the breathe, one observing the body... one making a refreshing lassi for the coding one... etc. ;))