Thanks for your responses!
I guess it would be true to say that, while I'm having a "really long" panic attack, the intensity isn't the same the entire time. But, on a scale of 1 - 10, it stays at about an 8 with frequent peaks to level 10 and above! So it definitely feels like it's a continuous panic attack.
My body has a REALLY strong physiological response. I can almost feel the adrenaline and cortisol and whatever else coursing through me. I start shaking and I feel really weak, my legs feel like jelly and I get lightheaded. My breathing gets really weird and I start feeling nauseous and get a really dry mouth and can't swallow properly. Then my thoughts kick in and I start feeling really terrified. Like just total and utter TERROR. I feel paralyzed, but I also feel very agitated. I feel extremely trapped in my own body and have strong feelings of claustrophobia. At some point I usually end up having feelings of unreality. Throughout I have a sense of terrible doom and, in particular, I feel as if I am about to drop dead at any moment. Fun....! NOT!!!
Typically I will try and lay down in bed, but that often makes it worse. After a while, I'm usually able to be still, but then I keep getting waves of panicky feelings and thoughts. Even after the worst is over, I generally feel really ill for the rest of the day, or more.
Luckily, I don't have panic attacks like that every day!! I have had two panic attacks like that in the past month. Inbetween I've had the milder, quicker variety.
Thanks for sharing.