These are not as bad as you seem to think. See how your shirt on your back goes from smooth to rippled? That's a good sign. And is enough evidence of "Step 4" for you to progress the weight from here.
There are some things to work on, however.
Look at your hips. See their position after you bring your shins to the bar? They need to stay there when you start to pull. Instead you are rocking them WAY down and back before you pull. Don't do that. You say that the starting position is very uncomfortable. That's right, it is supposed to be. Resist the screaming urge of your hamstrings to drop your hips as you squeeze your chest up.
It'd be nice to see your stance and set-up without the plates in the way, because I suspect you may be setting up too far from the bar, so film from the front quarter as requested in the sticky at the top of this subforum.
Last, why did you bail on that last rep?
Keep on working!