I think because I have constant anxiety (overactive amygdala I
  think - the fight/flee/freeze mechanism is _always_ running in
  super-high gear) - I have to practice it from the moment I get
  up to the moment I fall asleep.

  It's linked up to my breathing... if I forget... I get chest
  pressure, ears get red, I start to get wrapped up with whatevers
  happening in front/around me... other people's problems become
  my problems... and.. it's just awful.