Look at the connections for your front turn signals--they can become a mess.
Do you blow a fuse with just the park lights on and no headlights (the first stop on your headlight pull-switch), or do you need to pull it all the way out and have the headlights on for it to blow?
If it only blows when the headlights come on, the check the headlight paths/connection.
It sounds like, however, that it blows the fuse in the first position, in which case I would start at the front turn signals as they also contain bulbs for the running/park lights.
Next, check the rear tail lights and turn signals. If you're lucky, your short will be somewhere easy to get to when you pull those tail lights off.
It sounds like you may have some wires melted
Ill pray to the bus gods for you