I can relate to this all too well. I'm not sure if you have had any luck recently? But I've decided this is my last year to get this sorted, after dealing with it for almost half my life (I'm in my 30s).

As someone who is naturally social and has been part of many activities this condition has ruined so many key moments in my life, which I can't let it continue to happen.

Like you I never truly know when the smell might occur, as much as I watch my diet, take all the vitamins, and gone for countless dr/ dentist/ hospital examinations (they think I'm it's all in my head). Fortunately I have shared my frustrations with family and close friends who have been supportive but also can't smell/ understand my daily struggles.
Therefore this year I am determined to get some answers, as I had given up and just excepted my fate and been living with it for the last few years.
I will update the chat with any findings...