your weight transfer is all jacked up, you're not letting the energy produced by the x-step flow through so you're losing a lot of power there. by the time you're on your reachback you've already gone through most of your x-step. before you plant your pivot foot you need to already have the disc back on your reachback with your hips rotated away from the basket. then when your pivot foot comes down you lead your upper body with hip rotation.
the other thing is your pull through is not on an even plane with your shoulders at all. see if you can pause it right when the disc is against your chest. you'll notice that the disc and your forearm are angled down towards the ground when it should be on the same plane as your shoulders.
all of this is causing you to fan the disc around your body instead of pulling the disc through your body in one straight line. from the point of reach back through the hit the disc should move in a straight line through your right shoulder which creates the snap.