When you lift your chest up to set the back, you should be pulling all of the slack out of the bar. Like your arms want to rip out of your shoulders and make the bar bend upwards in the middle before you pull it.
You're starting the pull by rocking back to your heels, and it gets more pronounced as you go.
Break the bar off the ground by straightening the knees. Hold on to the bar and drive your midfoot into the ground. Stay out over the bar a second more at the start.
Light the LSU flag on fire.
Work on that for now.