You don't have to do perfect reps. Don't quit if you can still get 3/4 or 1/2 ROM. Having a bench available to go straight into negs, assisted machine, and variable hand spacing are all good ideas. Fool around with supinated, pronated, and palms facing type grips as well.
If your row is better, get setup with feet elevated and lower them by a couple inches each workout. Never tried this but heard it recommended.