[URGENT] What does this mean?

[I love]

Well, there is this girl i REALLY like, and I don't know if she likes me back... i've been in love for about eight years... and haven;t given up.
So firstly, I am always nervous and act awkward around her, BUT... she acts the same; her best friend wrote on my twitter "[MY NAME IN CAPS] LOVES [CRUSHES NAME IN CAPS], the conversation went on and on and she eventually said this is awkward and it's always been awkward around us.
When I talk to other girls around her... or flirt, i guess, she get's all annoyed? and reacts with ignoring me, or speaking with eveyr male in the class but me... yes, it's what we ALWAYS do.
A week or so back, I thought she was angry at me, and avoiding me... but instead, she thought I WAS angry at her, this was a mistake... but do girls care if you're angry or not at them?
All her friends say to me "Ask her out, who knows? You may get a yes!" does this mean that they know she likes me?
She claims that i'm a flirt with all the reasons stated above...
She says that she likes another guy, but when anyone around me and her says the fact she likes him, she punches them, but when i'm at a distance she doesn't.
She looks at me in classes, and when I look back at her (it's rare, I promise you) she looks away REALLY quickly.
She asked me to walk with her a couple of weeks back, and I did, but I stayed silent as it was a REALLY short walk.
When both of us walk pass each other, I always face the left or right whilst she faces the other, avoiding eye contact... I avoid contact because i'm just nervous.. but why does she?
How do I start a conversation with her, it's awkward, around any other girls, I can DEFINITELY talk easy with them, but this girl is different, I can hardly say a thing.
Thank you