I believe what you are suffering from is sleep paralysis. It’s quite a common thing and super scary, I too have gone through this terrifying experience. I had a very invasive test at the time that left me rather messed up and later at night I woke up and quickly realized I couldn’t move or speak, to make matters worse I couldn’t wake up my partner. What seems like a eternity I passed out and felt like I might have had a stroke but all the research indicated sleep paralysis. I think it’s caused by stress and the mind can play tricks with you, I know you also mentioned having shock treatment and I also had them in my younger years from severe depression. I do remember they caused memory loss but temporary. It’s possible that you experienced some hallucinations perhaps due to the treatment combined with sleep paralysis. I would speak with the doctor and let them know what you’re going through, they may have something for you to ease these symptoms. I hope everything will work out well for you, good luck 🤞