Just throwing this out there, but for anyone else that has experienced waking up and being unable to move/feeling held down, it's called
sleep paralysis and can often be accompanied by hallucinations. I've experienced this myself once at night nearly 10 years ago, but cannot explain a daytime experience while using the pc two years ago.
I am an atheist and am all for science, but I've had some experiences I can't explain (I've also been told by many that I have a light shadow). A not so scary recent-ish example would be shortly after my son was born, my father-in-law made many threats to me including to "throw" something on us, boasted about being part of a group of people that would handle me "dread" and fix me "good", and claimed to have my son's and my information (not sure if he was referring to our raasi info my husband gave him) and was going to make the call to put things in place to "deal" with us and make my son suffer as he laughed and happily claimed that he had intentionally been spiting us to make my son suffer all along.
My husband was at work and could not come home at once, so I stayed in bed with my son all day. While playing with him I suddenly felt my back grow very cold (I was previously in a constant state of overheating) and my chest felt heavy and constricted, making it hard to breathe. I swallowed hard, feeling fearful for no reason and told myself I was being silly and it was probably post-partum hormones messing with me. I was scared to move for some reason and then realized the bed behind me felt weighed down as if someone was lying there, but I knew we were alone and the door was locked so I continued talking to my son and he turned his head from my face to look down past my shoulder in the general area behind me and pointed. I thought I heard some whispering into my ear coming from behind me but I told myself the two of us were alone in the room and it made no sense. I told myself we were alone, the place was very hot, and I was probably hungry or tired or too stressed but my back still felt cold, it was still difficult to breathe, I still felt the space behind me weighed down, and I could swear someone was whispering into my ear from behind me. I kept trying to distract my son but he continued to turn his head to look behind me and point at the area behind my shoulder. Because I'm a wuss with previous unexplained experiences I did not turn around, but I decided if something
was there I might as well throw in some "protection" because there was nothing else I could do really. I said my godfather's prayers, chanted some mantras, the St. Michael prayer, and prayed generally to protect my son and myself. My husband seemed skeptical when I told him about it but a couple weeks later he dragged me out of bed terrified because he saw tiny little scratches on my back. His exact words were that it looked "like little claw marks". Before telling me he asked me to reach the spot and I couldn't, I usually slept with my back to a wall, and until he pointed it out I was oblivious to it.