9 month old labrador jumps up and bites, really hurts and can't seem to snap him out of it.

Same thing for me, my 10 month old female loses her mind on walks and at home, jumping, biting and not listening at all. I have had some limited success with teaching her the command scatter (taught at calmer moments with her) where I say scatter and drop a small bunch of treats on the ground around her, this tends to distract her and get her focused on the treats and not me. I have also found that walking towards her as she lunges at me tends to knock her off balance and get her back on four paws, backing up definitely makes it worse. I also have tried to teach her the command watch (where she focuses on a treat I hold up to eyes and she will, in her finer moments, sit and calm down while doing this). That being said I have had labs for 30 years plus and this one has been my most challenging for reactivity. She is very loving and sweet when she is not acting like a crazy tiger. Don't give up on your sweet lab, they want to please you they are just crazy puppies for a long time. I find obedience training everyday helps even if you can do 5-10 minutes helps.