A video from the rear oblique, as mentioned in the sticky, would be more instructive. What I can tell you is that you are divebombing into the bottom, relaxing, and often going too deep. You then push your hips back instead of up. While I cannot see your head, I would bet you are looking forward, too. Here's what we need:
A better video angle.
Descend slowly and under control.
Get tighter. Be uncomfortable.
Drive your butt straight up while keeping the bar over the midfoot.