I had accidentally taken an overdose of medications and was alone at the time.  I was in bed, too sick to call for help.  Suddenly I realized I was floating through darkness, slowly at first but accelerating as I continued.  I don't know how I knew, but I was aware that I was going through what I can only describe as "planes," each one leading to the next in a progressive fashion. Each plane consisted of total darkness, with each becoming darker than the former. Each plane was characterized by a different looking entity, as if each were the "master" or head of their respective planes. Each entity looked different but all had an appearance that fits the typical description of a demon (grotesque and animal-like).  Likewise, I knew these creatures were very evil, although none interacted with me. As I progressed through each plane, I was aware that I was headed somewhere, but didn't know the exact destination.  Although I felt nothing physically, mentally I was deeply distressed because the darkness intensified and feelings of doom worsened with the passing of each plane. I can only describe the feeling as a total absence of ALL that I'd ever known as "good,” such as love, pleasure, peace, colors, the stroke of a pet's fur, etc.  I don't recall being able to breathe, but was aware that as the darkness progressed, so did the absence of air, as if I was suffocating.  I had the feeling that it was eternal that I would be in that existence forever. I felt as though it was what scientists call a "black hole," an area void of light and time.  I came to a point where I no longer felt I was passing through planes with the demonic entities I'd seen; they were no more. I was simply floating through deep, dark space, yet I still felt I was moving toward some unknown destination.  For the first time, I found myself able to think a thought and I cried out to God to save me.  Instantly, I was removed from the experience, and I was merely in a sleep state. I remained that way for about two days, after which I awoke and learned that during my experience my mother had come by to check on me and I was taken to the hospital for treatment. Thirty years later, the experience is as vivid and real as it was then.