Also mention that I was primarily hit with his right hand with the hard bony part of the base of the hand to upper middle part of my jaw. The second hand did not hit me as much but rather stopped the rotational movement of my head right in its tracks. (im not sure how easy this is to picture).

Im kinda worried because my head was stopped and thus did not have the opportunity to conduct a full motion which if I understand correctly would have reduced the g force. My friend has very large, strong, heavy arms and hands

I remember watching a video of guy at a party being punched in the face simoultaneously by 2 girls on either side of him. He was knocked out cold from this.