Nail growth help! I keep bitting my nails!?

Well i want to make my nails grow longer but they wont cuz i keep biting them my cuticles look like poop cuz the skin is just standing up so i have an urge to bit it off which hurts! also my nails dont have not even a tiny bit of white cuz i bit them so much!please help me, any polishes that i could z use to make them grow faster! any home recipies to make them faster and stronger? plz help me answer ASAP PLZ!