Actually it could have been less than a minute. Perception of time is usually distorted in dreams. I'd guess it was just a nightmare, I had one kinda like this one few months ago.

I was in my bed, just like if I woke up, except I felt a presence standing by the side of my bed. So I acted like I wasn't really awake, even if I knew the person (thing?) would be waiting 'till I woke up. I think I felt the presence of some others passing by my window, but only this one seemed to care about me.
After a few minutes, I felt that I couldn't do anything, so I decided to just raise my upper body and look at the guy.

It looked stranged, a bit like Munch's Shout, a bit like a mummy, a bit like the first victim we see in Ring. And the only thing I could do was shout the hell out of my lungs, straight in the face of the thing, while it just stood here and shouted back at me.

Then, I don't know why, maybe because I was shouting louder than him, everything (that's him, the others outside, and a blueish darkness filling the room I noticed only when it disappeared). And just at that moment, I woke up, my upper body raised, in my bed. And strangely, I had the feeling that the thing that was shouting at me wasn't harmful after all, maybe it was even protecting me - and I scared it away.

It may not have been my worst fear ever, but it sure was in top ten.

And I still don't know what all of this meant. Some similitudes in your story and mine lead me to post this, maybe it can help you understand something. I don't know for myself.