Loss of control, duty and responsibility, ego-related conflict

A panic attack is a sudden feeling of extreme fear caused by a wounding event, stressful life change, or triggers within the character's environment that remind them of past trauma. They also can come on with no apparent danger or cause. The body's response to real and perceived danger is powerful, resulting in extreme physical reactions that are instinctive and hard to control. Attacks can occur in isolation (from a specific circumstance) or they can be recurrent, as part of a panic disorder. Either way, these attacks are so terrifying, they can trigger a fear of having more of them—specially in public, where the character is exposed.

Being unable to think clearly
Feeling disconnected from reality
Needing to make a quick exit to someplace private
Uncomfortable physical responses, such as an accelerated heartbeat, sweating, trembling, nausea, and shortness of breath
Difficulty walking and navigating because of dizziness
Having to hide the panic from others
The character worrying about what others will think if they find out about the attacks
Not wanting to be seen as weak or fearful
Being embarrassed by an attack that comes on in public
The character calling an ambulance because they believe they're having a heart attack 
A costly medical bill after being treated for a suspected heart attack