I've definitely seen worse squats, but you do have a tendency to flex your spine a little. Not a lot, but if your back is bothering you, flexing while you move is not a great idea. Don't go so deep. You are almost overdoing the look down thing. Don't look down more as you descend. Pick a point a little further away from you, 3 to 6 feet, and focus on that. As you descend, work to hold your spine in extension. Think: tight. Strongly consider getting some lifting shoes.