Amazing HI's turns into very strange experience

I was just curious if anyone has had HI's like me. Last night i took like 6 mg of melatonin about an hour before i went to sleep so i was a bit drowsy when i went to bed at about 10. As i laid in bed i felt like i could wild and i started having some mild HI's. Then all of a sudden i started seeing vivid images of beautiful landscapes for split seconds at time. i saw vanilla skys along with amazing grassy hills in the foreground. Then all of a sudden i saw another one and i tried to hold onto it and after about a second it went black and a flash of red light blinked and covered my entire field of vision. It reminded me of a bright red light flashing on right in front of my eyes. Needless to say it was pitch black in my room and i have nothing in my room that could flash such a bright red light. I have had this experience before but nothing as vivid and as bright as this time. After i saw this i felt scared for some reason. I thought maybe something flagged me for being too good at seeing these images or something cut me off because i was about to wild with no rem sleep. I know that sounds crazy but at the time i was trying to reason out any possible explanation for it. It was so strange and unexpected that i felt fear from it and my heart began to race for a few minutes. I could not get back to the HI's i saw before the flash of red light and eventually i normally fell asleep. Has anyone else had an experience like this??