I don't have "panic attacks", I'd call them "doom attacks" or "depressive attacks". I don't feel afraid. It's just a heavy blancket of doom that comes without warning in like less than 10 minutes:

 I just feel entrapped in a situation when no one can help, everyone will realize how shitty I am, people will be disgusted of me, my past has been a failure and my future will be one too.

 So start the suicidal thoughts. And they grow. And grow. People who I love will KILL themselves because of me. Random people on the street pity me, no, they HATE me, they want to KILL me! No I need to kill myself now. I need to do it now".

 Then, as nothing ever happened the blancket lifts. I'm again perfectly normal in a few minutes. It's like someone flipped a switch in my brain. What I thought before was clearly just an episode like any other. I can recognize them, but I'm never ready.