Catch43,
My observation could be because of the camera angle, but it is almost like you are stepping too far to the left and not enough towards your target. Then on your follow through you fall away to that side.
Your feet should be square when you receive, then when you jump pivot your right foot should land out front and in the middle of where your feet just were in the receiving position. You should be gaining ground with your right foot but not lunging. In the video, to visualize, it was almost like you were stepping around a bucket with the right foot.
Then your left foot should stride directly towards second. Staying low is a good concept but imagine yourself uncoiling out of your crouch on the way up so you have the ball right behind your ear ready to throw as soon as that right back foot hits the ground from your jump pivot. Then you explode toward the target on the throw.
Just think of where the ball goes when a pitcher falls too much to either side during and after delivery. It is the same concept.
You can practice the whole jump pivot up to ball release over and over again without throwing if you prefer.
Watch some catcher throwdowns on MLB.com (Search for MLB Draft Central) and see how some of those catchers do it.
Others on here will provide other advice, and I hope you get the right solution. Then you can also seek some local catching coach help if you want.
Good luck.