Insomnia sucks in general when you get to the point of panic attacks and I'm sure thinking you can die from it wouldn't help. I can't imagine being awake for months at a time but it's pretty terrifying knowing there are people who die from it.
I stayed up for 70 hours once (I can't sleep sitting up, and I was on a long bus/rail trip), and in the last hour before I got home I was actually seeing people walking around in the empty train with me.
I remember back in 1998 or so when I used to post on the World Wide Warez Board, there was a thread where two or three different posters claimed to have chronic insomnia and have been awake for 8+ months. It was one of my first experiences of Internet drama.