I've experienced this a couple of times, but it's been fifteen years or so since the last. I think it happened once or twice when I couldn't even open my eyes--as I recall, I was aware of being awake, but completely unable to move. I have no idea what any of the dreams were, but I rarely recall my dreams.
The one time I remember specifically, I managed to get my eyes about halfway open, and saw somebody cross the room. It was a gray shape, somewhat ragged, and it glided across my field of view pretty quickly, like someone walking fast. I remember being terrified that someone was in the room and I couldn't move. My eyes closed again, then opened, and I could move. And there was no one in the room. I thought I had seen a ghost--still not convinced I didn't. I had no idea until just now that was a common phenomenon.
As far as stress, all of them happened during a fairly stressful period in my life--I was an undergrad at a pretty tough school. But not the most stressful--it never happened while I was at war, or fighting with my wife, or worried about finances, or when one of my kids was sick.
And I have never had an anxiety attack.
Hope it helps.
HN