Set-up: Raise your hips until you can extend your back. It should be at least flat. Practice per SSBT p37-38 until you feel it.
Don't roll the bar back to you. place the bar mid-foot, then bring your shins to the bar. Chest up might help some here.
On the negative, look at the bar path. You are breaking at the knee before the hips. Bar path should be straight in both directions.