As someone who dabbles in mushroom based psychedelics you are right. The sudden awareness of yourself, and even moreso the sudden awareness of 'not yourself' can be pretty frightening. I have had bad trips before, and they usually began with an untethering of yourself. Once you start floating outside of your life/personality, you can become very distressed with what is left. It can become almost scarring to see yourself from afar suffering so badly, but that be not yourself. It's hard to put into words, but that experience of intense disassociation, and the pain of being an observer to it is very real.