Fantastic critique by Kayty. I will add one thing, and that is your seat. You're very tense through your entire leg, which is causing your butt to come out of and slap the saddle each stride. Your knee is also completely off the knee roll; while you don't want to GRIP with your knees, you want them to be in contact with the saddle, not be all loosey goosey. You want to loosen up your hips, and allow your pelvis to move WITH your horse's movement, rather than be rigid and have your butt slapping the saddle. I think that stirrup-less work would really help you out here, as it's very hard to brace against stirrups when you don't have any - hah! Think about rotating your toe to point forwards instead of out to the sides.