Help! We have been dealing with head lice for 3 weeks!?

when I was little I got head lice from my cousin. my hair was SUPER long, like past my bottom :P my dad sectioned off my hair and went through it EVERY night for like hours, it was bad. but one thing we did was, a few times a week we would put olive oil all over my hair and head and I had to sleep in it. although it was quite obnoxious and uncomfortable... it works! the reason is because it suffocates them and they loose their grip on you hair and come right out when you comb through. also you've gotta make sure that tour not just focusing on the nits, but also on the little white eggs..because you do not want to let them hatch! hope I helped, good luck!