I agree with Larry.
If you take a look at previous posts, you'll see many, many of them are breathing-related.
I experience/d this as well.
Sometimes when I'm anxious I'll feel that way, and being aware of my breath, in the moment, conscious-breathing, helps me to realize I'm actually breathing very shallow, not utilizing my full lung capacity. This, in turn, causes hyper-ventilation, which also starts to muck about with O2/CO2 exchange, and voila,...it exacerbates things more.
So it is a cycle. Grabbing hold when you start to notice will help, don't just suffer along until it's driving you bonkers.
S.C. has awesome resources...they really do work!
My time for tears will be at my Victory...not at the start of the War. ~~Vickie