Is this a sleep disorder or epileptic episode?

[Kardouche]

Sometimes when im falling asleep(not yet fully asleep,in and out of it,semi conscious) and already dreaming, ill see something that causes a great feeling of fear in me, ill then begin to fight falling asleep as i get this feeling of dread because i know what is about to happen
which is like something completely gripping or overcoming me(like a prescence), a great feeling of fear or terror, complete immobility or paralysis and a violent shaking experience in my brain.All this lasts about 5 seconds as i fight to get back my body from this terrifying experience. I am not sure if this violent shaking like experience is physical or not but its there i can feel it all over me though i dont know if my body or head shakes as well in reality.from what ive read im not sure if these are seizures because im not epileptic. And these episodes are triggered by something dreadful or something negative  that ill see in my dreams as im falling in and out of sleep followed by that intense feeling of fear,dread and then this "prescence" overcoming me. During the process i am paralysed but fully aware of whats happening(its like i become fully conscious from my semi conscious state),i actually want to scream for help but im unable to do so.its almost like sleep paralysis except mine is accompanied with a violent shaking of my brain(feels like this) or my head and an intense feeling of terror.i dont lose consciousness afterwards rather i wake up completely. Sometimes ill hear voices and it often feels like an evil experience.The whole thing is rather horrifying and ominous .This has been going on for years now but they occur irregularly. What could this be?

[AnxiousNoMore]

No one can diagnose you from here so see doc. Could be just a nightmare.

[Kardouche]

Im starting to think this could actually be a nightmare(from the way ive described it). I cant believe this  never occurred to me before.But the very same nightmare all this years? Though ive realized that if my brain/head were to violently shake in reality that would be dangerous and concerning. Anyway thanks