Iphone 3Gs, apple logo keeps on flashing, since it tried to update the ios to 6.1?

I tried to update ios via Wi-Fi on iphone… The loadding bar went up for a bit, and then the apple logo just keeps on flashing…
i tried using redsnow to just boot, but it takes me to itunes, then RESTORE is all there the option. Then since i have ios 5 it starts downloading the ios 6 and finally when trying to install it says… Error, because my iphone is JAILBROKEN so netiher i can do sth from itunes nor from iphone itself, m stuck… My parents are going to kill me if i don't fix it. So please help me

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