Sorry if i repeat things that you have said already.
Your lower leg has come back. It looks like you are pinching with your knees.
Try gripping with your calf instead. Also try some no stirrup jumping and no stirrup work to strengthen your base.
Your hands should be further up on his neck, and it will give you a less scrunched up look.
I can't really tell, but if your hands are open, close them.
Good job for looking up!
I think with a little more work, you'll be doing great!