We need pix.
Honestly, being able to 'see' what you're doing will make it so much easier to diagnose than trying to guess.
For now, though, my guess is the rear drums still need the shoes adjusted. Your brake pedal is going all the way to the floor because the cylinders are using up all the fluid in the lines but not encountering the resistance of the shoes hitting the drums, which would firm up the pedal at the bottom of the throw.
Honestly, being able to 'see' what you're doing will make it so much easier to diagnose than trying to guess.
For now, though, my guess is the rear drums still need the shoes adjusted. Your brake pedal is going all the way to the floor because the cylinders are using up all the fluid in the lines but not encountering the resistance of the shoes hitting the drums, which would firm up the pedal at the bottom of the throw.