NEED SERIOUS HELP NOW!!!! please!

2004 4.3L 4wd. i just installed a stereo system and now the thing is not right. it starts but slow and low rpms then builds up. it wont shut off with the key, just keeps running. when you put it into gear, it dies out. wtf!?!?! i ran a wire through the firewall next to where the main harness comes through, ands then through the boot under the hood. my only guess is that i hit some wires somehow??? i was extra careful not to. please someone help, im stranded and got no idea what to do?!?!?! i appreciate any suggestions and input, thanks guys.

Remove the wire you ran through the firewall.