Sleep Paralysis or Dream?

[xdream]

Okay, so last night I tried the Wake Back To Bed technique, and although I didn't have a lucid dream went to sleep for a short amount of time (seamed like about 2 minutes) and woke up to what seamed like sleep paralysis. This happened twice during the night. When this happened the first time, I suspected that it was sleep paralysis as I felt and heard a vibrating which made me feel anxious. I then saw a vivid, correctly coloured outline of the cartoon of the joker(which I saw in a batman film recently) on the back of my eyelids. I was too scared to verify by trying to move and I remembered that somebody had told me once that if I held my breath I could escape from the paralysis, so I tried this. The vibration continued and so I tried to move my arm and I could buy only very slowly when I really tried. When this happened a second time, I was completely unable to move my body and when I tried to move my arm I just couldn't and when I tried my arm felt slightly electrified. Also, I felt and heard a vibrating, which slowly got more intense and 'climaxed' then slowed twice. As I had read about sleep paralysis, I was sort of scared that it would be as bad as it is usually described, so I started to panic which raised my temperature, heart rate and breathing. Half way through(before the second climax) I saw the outline of some demonic monster on the back of my eyelids(which I knew wasn't real). I then remembered that I had read that if I struggled that the experience would only get worse, so I calmed myself. I then opened my eyes, the view was normal. The vibrations then slowed and stopped. I was then able to move, and I do not recall experiencing any 'waking up'. Also, during these two experiences due to the fear and anxiety mixed with the vibrations and the inability to move, I felt like I feel while on a roller-coaster. I did not feel any evil presence, however. I suspect that these were simply dreams because I have had sleep paralysis in dreams before. I know that they were dreams because I was lying up against 2 pillows when the paralysis occurred(which I never sleep like), the actual time was the middle of the night(but the light was on when I was looking around), I didn't feel the electric feeling when I tried to move and I remember continuing the dream after the paralysis and waking up later. I was just wondering if my description of SP matches that of others, if it were likely that it was a dream and if anyone had any other observations about my experiences. Thanks,