Im in a really complicated relationship so here it goes?

So this girl I like, is sending me mixed messages, sometimes she is nice to me, some other times she is shy when I'm around blushing, that sort of stuff, sometimes she tries her best to ignore me, sometimes she is just so mean to me, signs she is giving me like touchin my arms eat my food making me jealous, she gets angry when I talk to other girls, so then I asked her to go to lunch with me then she meanly said to offer my suggestion to other people, i'm confused please help...? oh yeah and the next day she waved at me... and today she talked to me again like she has done something wrong that kind of feeling...has anyone experienced b4 if yes how did u deal wid it?