a

.

You have to work on keeping your shoulders depressed (pulled down toward your feet) throughout the movement.  You are letting your back sag while trying to reach further down, don't do that. actively pinch your scaps together at the bottom and spread apart at the top keep your trunk solid.

 

I found that my body didn't really know what it should feel like until I tried doing some reps with my knees on the ground then a light bulb went off and my form looked much better.  Or even just standing up stick your arms straight out, tuck your tail, depress your shoulders and then try to spread and pinch your scaps.  

 

The swivel hips look pretty good too me.  If I could get as far as you are I wouldn't practice with any lean, in the end mastery is with ass to grass.

.