I reckon that just as physical exercise is necessary for a healthy body and mind, so too can breathing exercises be.
They help you focus, give you time out, and can distract you from a binge. Also, if they help with circulation of oxygen to your organs, including your brain, ain't that a good thing?
There are many sites out there, if you just search google. But for starters, here's a very straightforward site with a simple exercise: http://www.stress-relief-exercises.com/deep-breathing-exercises.html
I think if we can work such things into our routines however busy we may be, we can all start to relax and combat that terrible anxiety :)
Good luck everyone! xx