Your polygrapher's claim that people who control their breathing during a polygraph examination are trying to hide something is not necessarily true and is unsupported by research. This notwithstanding, many polygraphers consider controlled breathing to be a "countermeasure" and hence a sign of deception, and your polygrapher was indeed attempting to extract a confession from you.

Based on what you've written, I cannot venture a guess as to whether or not you passed. To be better prepared for your next polygraph examination, see Chapters 3 & 4 of The Lie Behind the Lie Detector, which may be downloaded here:

https://antipolygraph.org/lie-behind-the-lie-detector.pdf