HELP!!! Crossed terminal wires when installing new battery

I know I know I'm a dumbass. Now that that's cleared up, I really need some help. I accidentally connected positive to negative and negative to positive when putting a new battery in my 06 Cobalt. It sparked a bit, then the horn went off and there was a big puff of smoke from the engine. Immediately unhooked it and stood there for about two minutes in disbelief of how stupid I am. Looked under the hood and one wire is completely fried, not sure which wire it is. Please help!!!*

its probably the main wire from the fuse block to the alternator. the diodes in it act as a dead short when you hook battery up backwards. should also be a large 50-90 amp large main fuse in the fuse block that may also have blown