you are poor Squirrel that you have to suffer from panic attacks. As a quite anxious person, I've got my own experience with both free flowing anxiety and panic attacks. So I can relate to your situation. *hugs*
I've found that overall level of anxiety is connected to our current life situation. My last period of stronger anxiety was connected to my promotion. Suddenly I had to take care not only about my own job, but I had responsibility for other people's work. And as a person that needs to be in control all the time, something like that hit me really hard. Then I had an accident during my martial arts training, got concussion and voila, panic attacks appeared. It happened back in 2014.
What I've learned is that anxiety is not going to kill you. It is just a protective mechanism that is very handy in life threatening situations and it was important during prehistoric times. But it is not so usually useful in current world of social interactions and information overload. Anxiety, as any other emotion, is connected to vegetative (bodily) symptoms, automatic thoughts and specific behaviour - usually constant reassurance or avoidance. All of those modules are interconnected, interact and enhance each other. Activation of any of them can lead to vicious circle and panic attack.
Higher level of arousal ->excessive self-monitoring -> detection of otherwise undetected bodily symptom, for example one irregular heartbeat -> automatic thought "something bad is happening to my body -> anxiety -> even hither level of arousal -> ...
My strategy was to limit possible sources of anxious arousal, e.g. stop drinking coffee, stop reading and watching news.
Then I tried to create some set of positive affirmation and begun to repeat them always when I experienced first step in aforementioned vicious circle. It took some time, but I was patient and slowly, my panic attacks begun to diminish.
I believe you'll be fine. Just remember: Panic is not going to kill you. Yes, it is unpleasant, but not dangerous. It is as unpleasant as, for example, cold rain.
I wish you to have a calm night-shift! *more hugs*