Did we almost die?

I had a very strange thing happened to me when I was in my twenties. My boyfriend and I were at a friend's house party, although we had went to bed fairly early, around 10:30, and we had not been drinking much and no drugs. We were laying in bed together spooning, cuddling, almost asleep when we felt numb and almost like our bodies and minds were melded together, couldn't move, heard a soft humming that got louder and louder, that turned into a chorus of seemed like a million beautiful voices crescendoing, singing one note, getting louder and louder (like angels singing, is the best way I can describe it) until it kind of reached its peak and then *pop * we startled awake.

We talked about it then and we both felt the exact same thing at the same time. The whole thing lasted maybe 5 minutes? I often wondered if maybe there was carbon monoxide in the air and we almost died? Although we both felt fine and we eventually went back to sleep and didn't die and there were other people sleeping in the house that were fine. It just always stuck with me that it felt like that might be the way you would feel if you were to die and go to heaven.