It's definitely time to come at the whole lift differently. It LOOKS painful, the way you're doing it now. If I were in your position I would read everything I could on deadlifting. One thing I learned from golfing is that sometimes just having the right thought in your head can change everything. You need to find that thought.
For me on deadlifts I've been working on feeling like I'm pushing my legs between my hands at the start of the lift. Just this small thought got my butt down, my back flatter, and my legs far more involved than they had been before.
The good news, I suppose, is that it does look like form is your problem. It could be a LOT worse, as we all know.
Current PRs at 242- 495, 345, 585, 1425