A ride from Hallstatt to an airport! Any airport!

Help!
I've been living out in the country by Hallstattersee for almost 3 months. When I arrived, I was picked up by a good friend at the airport in Munich and driven here by car.  Things changed (no need to spend an hour writing all the boring details, and you probably don't want to read them, either. lol)-- bottom line is, I need to get back to the U.S. soon, and I don't have transportation to an airport!

Buses and trains won't work; there are just too many changes to handle with all my luggage. So I have been trying to find a car to rent in Hallstatt and drop off at the airport in either Vienna or Salzburg. Amazingly, there don't seem to be any available! I mean not ever, not just on certain dates!

If you have any suggestions, PLEASE share them with me!
If you plan to be driving anywhere near an airport in about 2 weeks, PLEASE send me a message! 
I'll  plan my departure flight from whatever airport works for you around whatever date you're driving, and I WILL BE HAPPY TO PAY FOR GAS!

Thank you, bless you, hope to hear from you (whoever you are) soon!
Judith (recalibrating)