Lice All On My Head Or All In My Head?

Here's the deal,I was around my best friend's kids Friday & Sunday. My best friend calls Sunday afternoon and tells me she found lice on her daughter. I immeadiately freak out and go and get checked by the nurse nothing but dandruff. I used Rexall,Vinegar, Mayo, Conditioner without evidence of lice. I was wondering if I could have irritated my scalp? I haad my friend look and she only The saw dandruff that disappeared when I washed. my hair. It has been almost three weeks since the incident wouldn't I have known somethig by now? I have these sores in my head that my friend popped and said fluid came out I think the treatments I used brought them out. I have this "itch" going on to where its like prickles of heat on my entire head that I swear is lice running a marathon. My friends older two boys didn't get it and neither did she and she shares a bed with the girl. If they didn't get it how the heck did I?!?! A lice expert told me that not everyone that comes in contact with it gets it. I can't handle being one of those people that has piles of bugs falling out of their hair. My gf gave me a hug and if I have it she has it Sad She has eczema bad! Did I create an itch by treating something that possibly isn't there when I wash and dry my hair my itch goes away. If I don't think about it it doesn't itch but as soon as I think about it it itches. So much conflicting information on the internet. I pulled out my hair literally so could the it be hair regrowth or just the natural movement of hair.