URGENT MANAFOLD BOLT SNAPPED DRILLED TO FAR VECTRA 16V PETROL?

N REG VAUXHALL VECTRA 2 LTR 16 VALVE PETROL

SNAPPED MANAFOLD BOLT INSIDE HEAD. I TRIED TO DRILL IT OUT BUT I THINK I HAVE DRILLED TOO FAR AS WATER STARTED COMING OUT DOES ANY ONE KNOW HOW TO FIX THIS OR IS THERE A COMPOUND I CAN USE FOR A TEMP UNTIL MY AFTER MY HOLIDAY I GO TOMORROW

PLEASE HELP GAV