(freaking out might be a strong term, but my heart was racing, I was breathing heavily, shaking/shivering, etc, but still laying relatively still)
So to me the weirdest thing about an out of body experience was that I could observe my brain in a similar way to how I observe my hand right now. I can move my fingers around, and the hand is definitely part of me, but my hand does not feel conscious. So when having this experience it felt like my consciousness moved out of my head to the room and that I was observing how my head was processing thoughts while still being somewhat in control of those thoughts.