Your hand is one unit, not five. Each note played begs for hand movement, not finger poking! When your pinky stops naturally sticking out you'll know your hand is in better shape.
Well done with this difficult piece!I agree with pencilart3. Just want to add that it's not just a technical problem, but also a musical one: your notes all sound too similar, without the necessary dynamic shapes or contrasts. That's how "finger poking" comes out in terms of sound.In the second part, it's great that you play softer when the score says piano. But generally, you also need a greater difference in dynamics between melody and accompaniment.