My teacher accused me of cheating, what do I do.?

Ah finals week, one where you study for the biggest test of the semester until, oh i don't know, 3 in the morning (<--hint i did this). So, i'm a straight A student, this whole semester I have been teetering from B+ to A- in science cl, well guess what now I'm getting something around a C or maybe even lower. Here's the deal I was studying in the library (during free break) and i was really nervous, without thinking, i started writing answers on my hand, noticing this I said NO i'm not going to cheat. Then, the bell ring and i had to get to cl, no time to wash it off. I had forgotten i had these answers on my hand (my memory is quite terrible right now, don't know why) and the teacher tells me to switch seats with this boy so that i would be in front of her (it's a lab table and you can see under it). So i'm doing the test, doing really well, I get to about 3/4's done and she says come here, says what is this, and i freak and lie (/slaphead, i'm such an idiot) and says I was looking at my hand! (I hadn't at all, this is NOT a lie.) (Also, she already knew and didn't tell me, the librarian saw me and called the teacher, neither she nor my teacher said anything) then immediately goes you have a 0 (out of 300 points) so I tell my mom, we go to the counselor (what a waste of time) he was an a**. The counselor agrees with her when the only proof she has is her umption that i looked at my hand, she said I put my hand under the table (which i never did, the whole time my flipping hand was basically on my head, therefore i can't look t it at all) and looked, this was such a lie. So were still trying to find out what to do but I'm EXTREMELY upset and i don't know what to do. I called her and the teacher still won't change her mind and basically calls me a liar when I tell her i didn't look at my hand once. My parents arn't agreeing with me too much either because i had the words on my hand (this i know already was stupid), but i swear i didn't look (i couldn't anyways, my shirt had one of those thumbholes and the sleeve goes to about half-way up your palm) and the questions i was doing didn't even match with the question i was working on. (maybe i should do a lie-detector test) I had no intention to cheat and now I'm completely distressed. please help.