As i'm going up in deadlifting weight, i find my grip gives way earlier than any other part of my body, making me lose reps because the bar feels like it's slipping off my fingers. I tried incorporating hook grip into the exercise, and while the bar felt a bit more secure, I felt my middle finger was rubbing against my thumb nail and making it feel like it was pulling it out, and causing a bunch of pain, and no matter what I tried it always came down to that when the bar left the ground.
Any advice?
You have to keep doing it and you'll adjust eventually and it won't hurt as much. Or just use straps. I'm up to 500 lb and I use straps on my top sets, I have no shame that my grip isn't as strong as my posterior chain lol.