I discovered phantosmia reading your posts, seems like a very difficult condition. Does a saline nasal rinse using a neti pot bring some relief ? Neti pot rinse with Himalayan salt. I suppose that's something you've already tried ? Does castor oil or CBD help ? I hope you will find a solution, keep us posted.
But it looks like phantosmia can be caused by respiratory infections. So one thing i would try is colloidal silver, which is an incredible and very safe antibiotic. It must be easy to find in Switzerland. You can use it internally (drink it) and also using a nasal spray or with a nebulizer. That's the first thing i'd try, nasal spray with colloidal silver (10ppm or 15ppm) many times a day, and if it helps then it could be due to some kind of infection. Good luck !