I need some advise...

Being left out sucks, especially if it's a school activity which a big audience has to watch.
Try being もっと見る social and if anyone ignores while your talking then say "I won't be ignored, あなた listen to me pal, I'm the one talking here".
あなた should try being もっと見る demanding is what it is.

Stand up and kick their Ass! If your not going to be accepted naturally, then be accepted forcibly! Be the person that stands up! They start conversations, but あなた finish them! If they don't like you, then too dam bad! You're there to perform your role in that play, and they are going to like it! 表示する them who あなた are!

keep incerting your self until they notice あなた thats what i do annoy the shit out of them

I'm not good with advice, so くま, クマ with me.
But, to be honset, if I was you, I would keep to myself a little bit. I'm naturally shy, but this year, especially in my Chemistry class, I didn't know anybody and no one would talk to me.Yet, when they noticed me drawing, the other students came to me asking if I could draw them things, and well, they became social towards me.
So my アドバイス is to 表示する them your talent, what makes あなた special (in the play especially). It sounds corny but that's okay lol. If they respect and admire who あなた are, I'm sure they'll talk to you. If not, they just missed a big chance on getting to know some one truly unique :/ and that's their loss.

^again, I apologize, my アドバイス is not the greatist ^^;