I step back, it's hard to tell in the video. How far should I step back though? I step back maybe 18 inches. I know I shouldn't be fighting the weight though, should I reduce weight and get the form down?
A step back is not the same as a split nor is it a recognised variant of the jerk, it was a while ago when i competed in OL so i'm a little unsure of the exact details but i remeber moving both legs pretty much equally in front or behind of your body with a slight bend in each knee at the end point.
yes, the problem you've got is mostly your dipping too far, you'll just waste energy and so struggle more. just dip down slightly then do the leg drive, split and finish. drop the weight down a touch and just rebuild, you should be able to lift more than you do once you get the form down.
also could you post a side on video of the lift, or at least your cleans?
google split-jerks and some useful vids should come up, i think rippetoe has some