Rounding Back Deadlifts

Ive had issues with my deadlift for a long time. I’ve had 2 pretty good injuries that put me out of working out for a couple of months each time. Both times were me trying to get a big weight and rounding my back. Next thing, I’m on the ground waiting for somebody to pick me up. I realize everyone is different and I’ve seen people pick crazy weight up with a rounded back, but for me its a no go. Check the videos in the article and let me know what you think.

A) deadlift 3-3-3-3-3

B) 30-20-10
wall ball 20/14
toes 2 bar

C) 10-20-30
KB snatch 1.5/1 pood