my nose smells like fart

Hello, I have a problem that I can't solve: MY NOSE SMELLS LIKE FART when I BREATHE.

DETAILS:
- I have good hygiene, I brush my teeth, I scrape my tongue, I floss, I rinse my mouth.
- Nose washes
- I drink a lot of water
- I wash myself / deodorant / perfume
- I don't have bad breath from my mouth because I did the test with my sister... and I know that the smell comes from my nose because it sends when I have my mouth closed
- I went to see several specialists (dentist, doctor, I had a sinus scan, ENT, to see if I don't have a stomach problem but they found NOTHING. I am DESPERATE
- I also tested hydrogen peroxide with bicarbonate (it doesn't work for me)
Currently I constantly put vaporvicks in my nose to "mask" the smell but it doesn't help me much! I even bought essential oils of "cajeput" "peppermint" as advised but it doesn't work either.

The only thing I could blame myself for is my diet, I don't eat healthily so I don't know if it's because of that. So if someone is in the same situation to find a solution would you please help me? Because I can't take it anymore. Especially since at work they constantly tell me "who farted", even at home when I'm only with one person they tell me "did you fart?" when no. Even I feel it, it's unbearable.