Breathing excercises DO help.
But unless you want to sound like a choo choo train all the time
I reccomend counting doubles.
I've already mentioned this somewhere on here but basically in your head count double
pick any number you want
for example 1
1x2 = 2
2x2 =4
4x2= 8
etc.
go as high as you can
Then start over, maybe with a different number.

you'll look like you're thinking about something. Not avoiding the situation.
you can also do the breathing excercises with or without this.