mental images

i have read some of the posts related to this here through google and i would still like to ask this again, first time posting here, i am going to talk very casually because it helps me not to panic, but all of this is important to me, i hope this is the right place as it is a recovery thing

lately ive been moving to gifs, and several gifs on screen, some of them had certain subtitles/captions on them with "suggestions"- i guess, i've gone through hell out of fear that its somthing related to hypnosis and that suggestibility levels during arousal may increase and that i accepted the stupid (not empirical so cant really check= "becoming stupid" and things like that) suggestions even though i dont want to but.. will is subjective and "at that time i might didnt think so because i was focused" and hidden hypnotic suggestions and other terrible conspiracy theories that i hope my anxiety is producing and have no basis in reality
sounds kinda stupid but how will i know if i rejected those suggestions for sure?

now the second problem is the mental imagery, first off i've been told that not everyone experience this so if you experience the first part of what i say now it will be great if you mention it

in certain times at the day, minutes before sleep, daydreaming, and generally any time i'm in alpha state, i see images of some random images and scenes, if i try really hard i can do this at will even at alert state and just see the wonderful creative flow of images, above is the first part
when i started seeing gifs (not necessarily with captions) before sleep and seeing them for like 5 minutes, and then going to sleep, i've seen a CREATIVE FLOW OF IMAGES without trying to!!! just needed to close my eyes and i could see it, in contrast to what i described above where i needed to rest a little
(NOT GIFS THAT I HAVE SEEN, JUST RANDOM GENERATED IMAGES AT RAPID RATE, kind of impressing if it wasnt terrifying), this scared the shit out of me but it normally faded after a day
now it gets weird
this happened several times somtimes day after day, and one time i've did this under methylphenidate, the "did" was extended and more intense, about 20-30 minutes and as i predicted the "after viewing" effects were even stronger, and somtime in that night i kinda tried to shut down these images and just see blank, and it worked, but i needed to be "on guard" and it resulted me having a very bad time falling asleep, like i coudlnt relax
anyway since then i've moved to "regular" videos, and the last times have been intense aswell (long "sessions") and i could see those same terrible images upon closing my eyes again, untill i tried to stop it again, about 10 days ago and since then its like i dont think about anything before falling asleep, i dont see any images, not like in the first part and not in the second one, and i know its not natural because it takes me LOT longer to fall asleep and it is actually like suffering, just lying there thinking about nothing, i dont know if i'm still unconsciously guarding my thoughts and thats why i cant see any images, i am afraid of seeing these images again but i want the old images back, in these 10 days i've gone through much fewer "long sessions" and it was mostly just normal sessions of 2 minutes with random videos, my sleep is not satisfying at all
this was describing the situation
i know very little of psychology but i know that trying badly not to think about somthing will make you think about it, but the problem here is, if you experienced the first part of what i said, you know that to "start the engine" of the good images you have to release, you have to think about nothing and just let the flow go, i am afraid i forgot or lost the ability to do so, i hope to get a response from someone who experienced everything i said as according to "sources" 70% of population experience the first part and well.. the rest of the story is not so rare, i hope this someone knows what to do because i am terrified of this situation, should i stop watching regular things aswell and try to start the engine again? what to do if i encounter bad images after 1 day of not watching or even more days? was your visualization skill (without creativity, just trying to visualize something) impaired aswell?
thanks and sorry for messy writing