Thank you Mr. Robert.
Upon further review I know what I am doing wrong... mostly.
On the second part of the crack I am not turning my body (into the crack to the rear) and bringing the whip back behind me as far as I can before turning back to the front and finishing the crack in front.
I am currently doing the exact thing Robby warns about by not turning into the crack and taking the whip back as far as I can before throwing the whip forward, hence "hitting the back of my head / neck.
This is what I am going to be working on tomorrow.
When you're choreographing your life, sometimes you have to dance with the music you're given.