How do i get rid of lice?

well, im a 13 year old girl with long, thick, curly blonde hair and i keep getting lice... alot of people at my school have it and its going around pretty bad so ive had it 6 times this year and have it again. but its summer and i havent hung out with anyone besides my bf and he has like a buzz cut so i dont see how he would have it? ive been using Rid, and it doesent exactly work. my mom goes thru before and after i shampoo to get out every nit and bug she can find and and it seems to work until i find out i still have it a week or so later. i wash everything, bedding, clothes, hats, anything that ive been in contact with and i still and up getting it. so now i have it again and my mom is so fed up with it shes actually mad at me like its my fault... i really dont want to use Rid again because it burns my scalp and hair badly plus ive been reading some pretty scary stuff about it. so can someone help me please? im open to any suggestions besides shaving my head... my curly blonde hair is like my signature thing and i could stand to loose it. plus how would i explain to people that i had to shave my head because of lice? so please comment and tell me of any remedys you know. thanks(: