Head light issues 04 Jetta deisel

I have a 2004 Jetta TDI
The headlights all of the sudden don't work. when the switch is off the daytimes come on. when the switch is on the headlights go out. high beams work though. Yes I did try a new set of lights and same deal.... confused!!!

my second question is I only get 760km per tank and I hear many do much better... any ideas? already changed thermostat...
Any help would be awesome guys!!
Thanks