I had something like this happen to me once. It was like half of my brain was still asleep. The left side of my body could move, but what I was seeing with my left eye wasn’t real. I remember looking down the bed toward my feet and trying to lift my left arm. I could feel it moving, but the arm I was seeing wasn’t moving. When the hand finally got in front of my right eye, it suddenly appeared out of nowhere. Needless to say, I was WIDE awake at that point!
I’ve had this happen repeatedly since my teenage years. The farther I’ve gotten from that era of my life, the fewer times it has happened. I finally found that the best way to deal with it is just to consign myself to the hands of God and let it go. The feeling of a frenetic, tickly bubbling in the center of my brain increases to a point that feels almost intolerable and then ceases. When I was younger, that bubbling was accompanied by an increasing feeling of terror and strange oscillating sounds. But once I found that the best way was just to abandon myself to it, it’s not been a problem.