Need Wiring Help Bad!!!!

[Gunther]

My headlights, turn signals (all but the front left one), hazard lights (none of them), brake lights and horn do not work. I chose to fix this in steps, first replacing the turn signal switch (it wouldn't stay clicked on so I knew it would be bad, no matter the wiring problems). This went well but didn't solve any of the above problems, except at least now the lever stays where I put it. When I was testing the switch, the wiring loom leading to the switch overheated. I managed to disconnect the batery fast enough to prevent a full-fledged fire, but the purple wire is completely burned in two.

What the heck is happening? Bear in mind that my automotive talents do not extend very far into wiring, so please keep it as simple as you can.

Thanks in advance.