Youve got several issues there that are causing you problems, and some that will for sure cause you problems as you get stronger.
First, your starting position is off, youre back is rounded to begin with, and its only going to get worse from there if its already rounding at the start.
You also dont have a first and second pull, youre basically jerking the weight off the ground in one motion and racking it. When you start from the floor, the first pull is controlled, and the goal is to keep a constant torso angle to set up the second pull (the explosive part of the lifts). Think "push the floor away" until the bar passes the knee, then "jump".
Then, youre getting on your toes and its kicking you forward, and as you catch youre not unlocking the hips, youre trying to lean back to compensate. Its impossible to catch solid because you are off balance, you have to unlock the hips, even in the quarter squat position, dont lean back.
You can fix these issues pretty easily if youll take a little weight off and start from the top down. Hang power clean from the mid thigh, then hang power clean from slightly below knee, then finally power clean from the floor. Something else that will help you is to do a front squat after clean you do. Try to go right into it and not break the momentum, if you can catch in a full clean do so. That will force you to unlock the hips and fix your catch.
I would also not do the high rep sets, thats likely re enforcing bad habits as you fatigue and form deteriorates more and more. These lifts are like jumps, dont string together a bunch of sub max crappy ones, do one, re set, do another, etc. You can easily get the same volume by doing a rep, taking about 10-20 seconds to reset, do another, etc. You will maintain more explosiveness this way along with better technique.