Today I first woke up at 5:10am and decided to fill my head with thoughts to wake up. After half an hour I lied in the bed and started trying to sleep. I began half-dreaming after nearly next half of a hour (some kind of dream projection began when I was asleep; these projections differ from dreams because I’m awake when seeing them and I can stop them or change into daydreams). After few minutes of a half-dream one of H-DC’s started to repeat one phrase without end. Then everything started: I felt like my head was heavily shaking (I wasn’t moving though), I saw very vague strips “flying” on my eyelids and I heard rhytmic voices of something like percussion. That lasted for ~5 seconds and than stopped, but I didn’t fall asleep. I thought this feeling won’t happen to me in a long time, but I had another half-dream that also ended with a H-DC repeating quickly one phrase, which affected with these feelings, just a little longer and I felt it stronger. Could it be that I hypnotized myself? 
Edit: I have now an idea to express what I saw: it was like bad vertical hold in TVs, so the picture looks like an old-fashioned movie tape being rolled too slow, and you see these black stripes between frames flying from up to down. I had something like that, like the frames were black and these stripes vere yellow and vague. More - I think i didn’t saw them, they just… were.
I was so close…