Horse looks lovely - hind leg well engaged, reaching into the bridle, nice and straight. You are leaning forward, tipped and twisted to the left and your hands are very uneven. And you forgot to wear your helmet.
Nice looking horse.
He looks like he's got a nice collected canter, his feet are in sync.
Your left shoulder is turned in. This is going to be a part of him falling on his forehand.
Also your pelvis is turned in.
I recommend riding in circles, sitting trot, and working on keeping your shoulders straight and back. Also, when you're turning, keep your hands steady, open your pelvic bone and allow the horse to carry you around. This will help you sit back in your seat.Your leg is at the girth, just make sure you keep your weight in your heels and don let your toe get to out in space :p