cant see your video let me check a couple of points where is the bar on your back most tuck it were its seems to fit high on the shoulders if thats where its with you try dropping it down lower ,a high bar pushes you forward also before you squat find a focus point in front of you high on a wall leave your eyes on that point during the squat, if you look down you will lean forward also try concertrating on pushing the bar on the way up not thinking of your legs ,its push the bar push the bar, tend to push it backwards, so its take the bar low ,squeeze your shoulders together thus forcing your elbows back and strightening your back deep breath force your abbs against your belt ,focus point push your bum back and squat, to come up explode the air out push the bar and before you know it your up .easy