Bar is too far out in front of you. Review the set up for the DL in SS ed3.
Approach the bar, shins 1" from bar, bend over without bending your knees and grab bar (without moving the bar), bend knees until shins TOUCH the bar, squeeze your chest up hard, and perform the rep. Pull the bar up your body, the bar remains in contact with your skin the entire way. When the bar clears your knees, open the hips and stand tall at the top.
Additionally, when lowering the rep, don't do it so slowly, you're wasting a lot of energy there. On the eccentric portion, it's the opposite, bend at the hips first, when the bar lowers past the knees, bend the knees. This will put the bar in the correct location for the following rep.
Last thing, when you are doing this, you HAVE TO COMMIT. Don't stop pulling because it's heavy, it's supposed to be heavy. Lock down hard, squeeze your chest up, pick the thing up.