I always thought ghosts were real, but this was what actually got me to believe in them. A few years back, when I was little, I was trying to sleep in my own bed for once. At the time, I was really scared of the dark. For some reason, whenever I was about to fall asleep when I slept by myself, I would feel like some thing was watching me closely. It freaked me out.
Anyway, that night, I was sleeping peacefully until I just suddenly woke up for no reason. It was around two am, and was VERY dark. I knew my mom would get angry if I woke her up at that time, so I tried to fall back asleep on my own. The shadows kept scaring me, so I finally just put my blanket over my head, blocking out all shadows, and left a small opening to breathe from. Suddenly, a nasty looking face comes up to the opening, scaring the hell out of me. The face was purple and wrinkly, no eyes, and had fangs. It looked absolutely terrifying. It opened its mouth at me, as if it was going to bite me or scream at me, then closed its mouth. I quickly threw off the blanket covering me to see what was causing such a horrible image. Nothing was there. I remember panic and fear, but I have no idea what I did after this happened. In fact, I didn't even remember the day after this happened.
All I know is, it wasn't a dream, because I actually move in my sleep, whatever I'm doing in the dream, I imitate. A movement like throwing off a blanket would have woken me up.
This experience does sound horrifying! I'm not going to say it was your imagination, to date I can think of no time that my imagination brought forth something like this outside the dream state. And I'm not going to say you were dreaming either. I believe that you saw what you say you did, it's just too often that children hear those other explanations and makes them afraid to report any others that occur afterward.
Just remember that when you have children of your own, if you don't already, and maybe you will save someone else from experiencing the kind of feeling you get when your own parent makes you feel like you've purposefully told a lie.