You are only doing a half squat at the moment. You must go much deeper – until the crease of the hip goes below the top of the knee. This deep:
https://scontent-lax3-1.xx.fbcdn.net...52460786_o.jpg
Widen your stance a bit. Take a big breath in at the top and contract all of your trunk musculature around that breath. Sit back, lean over, and go lower. Keep holding your breath until you get to the top. Then take another big breath and repeat.