You should have shut off the power and call a Pro when you couldn't get the GFCI to quit tripping. That was your first clew, the second is Reds are too big to secure 2, 12 gauge wires, you should have used yellows from the start. If the wire nuts were put on correctly the ground shouldn't have been able to contact the hot at the wire nut.
It is time to spend a little money and be SAFE!! Call in a good pro that is experienced with pool wiring.
