Try air BnB and try to negociate. I don't think you get an appartment, but rent a room, easier...
I am in the same position here.. but it is really hard because when you rent a room, people don't really want to help you mit the necessary documents...but it is working for me, can't complain....even is beeing hard.
Try WGzimmer or in the public taffels in Migros, Coop, with free annoucements...
good luck