To me it feels the other way. I feel the breathing opens up something that allows me to release the anxiety. In the end it's probably the same just from a different viewpoint.
Basically before the anxierty happened liked this:
1. Minor negative stimulus appears. I could feel the body react.
2. When I inhaled, and not before, my neck would feel some tension. This would persist a bit.
I had ried breath holding before, but that just delayed the stress feeling. Instead, I:
1. Held breath and counted to 4 2. Exhaled sharply 3. Inhaled a bit, and counted to four 4. Repeat if necessary
Thr new elements were counting, and the exhale before inhale. Followeed byna knowledge that I had two more steps to do: inhaling and counting. Rather than merely an uncontrolledminhalation and hope of no stress.
Interestingly, I rarely need the breathing now. My bosy changed its reaction to the minor stresssors. Maybe I’m just less on edge and less reactive, and the breathing helped my body come down from that reactive state.
There were a couple other things that may have helped. I wrote down my main source of worry, and considered it in depth, worst case, odds, how to recover, and it became clear that it's not actually an urgent problem.
Don't know which one had the greater effect, I did both at once. But I could feel the 4*4 breathing blocking a physical anxiety response in the middle of one happening.