Anxiety/Panic attacks are a result of a fight/flight response unleashed to stimulus that really doesn't require it.
In the 21st century, we usually don't come across many situations in which your adrenaline needs to start pumping.
Usually the most easiest way to get out of the state of panic is to be still.
Being still and paying attention to your neck, which tightens when we are afraid.
I've noticed if I be still enough, and stop tightening my neck, it almost eliminates all thoughts, or brings em down to a manageable level. The physical symptoms die down later. But the thoughts are what are causing the reaction in the first place.
A form of meditation is just focusing on your breathing.
Blocking out all those thoughts.
And cardio is a must every day 25-30 minutes.
Not only does it relax you, but it makes sure that cortisol doesn't turn to fat. Which can be a bitch especially if you lift. All that excess demand on your body can sometimes eat away at the muscle you've worked hard to build.