Great advice!
Years ago I read a book on the healing powers of something so simple:
DEEP BREATHING
Available to all of us, 24/7 (except maybe during an asthma attack).

So many books, so many methods.
Make sure the exhale is twice as long as the inhale,
That was the #1 suggestion I remembered.

In for 6, out for 6,
Military tactile breathing,
-- Breathe in counting 1, 2, 3, 4
Stop and hold your breath counting 1, 2, 3, 4
Exhale counting 1, 2, 3, 4
Repeat the breathing
Breath in counting 1, 2, 3, 4
Pause and .... Combat Tactical Breathing

The Power of Conscious Breathing: Reduce Stress, Increase Energy, Sharpen Your Focus, And Experience Transformation through Breath. (The Power of Breath)
Part of: The Power of Breath (2 books) | by Sowmiya Sree

Interesting anecdote - on your own, you discovered deep breathing and nobody else in the house even realized what you had done.

Thanks for this post. :)