It's kind of tough to tell much from that angle but it looks like:
(1) You stride to the closed side and that results in a posture change as you bend at the waist toward the glove side to get squared up to the target. This posture change can mess with your control. Further, it tells me you might not be maximizing your velocity. It looks like your drag line heads off to the throwing arm side so I would suggest moving to the left side of the rubber to get your drag line to end on the centerline between the rubber and home plate. That will minimize the "corner you have to turn" to get squared up to the target. See if that eliminates the posture change. If not, you might want to adjust your stride to be aimed more directly at the target.
(2) You don't really get the hips going toward home plate until after the knee reaches the apex of the knee lift. I think you could get the hips going sooner and faster, you'll generate more energy to put into the ball using your body and be able to take some of the stress off the arm. Also, committing your weight toward the target may also help you get your stride going toward home plate.