I've been waking up at precisely 4 in the morning sometimes and having vivid and terrifying hallucinations and when they subside, I can't remember most of them. If I do certain things or lay in a certain position, I remember a part of it. This example happened today: I initially remembered a spider the size of a dinner table and thought it was still there so I turned on the lights and nothing was there so I laid back down. I moved into the fetal position and remembered something huge with tentacles at the foot of my bed, and I sat up and remembered my arms being split in half lengthwise. This has been happening my whole life every once in a while, but I recently noticed that it's happening increasingly often. I would like to know why this happens, and if it helps at all, I'm a 17 year old girl, living with my parents and they are not abusive in any way and I have never had something happen to me that would cause mental trauma. If you know what this is, please tell me, and thank you.