Can they test some of your saliva,or scrape the tongue where all that white stuff is?
I have not actually been tested YET, but after taking herbal antifungals for a week I had major die-off symptoms. You can't have the die off without having the yeast/fungis in the first place. You may be able to experiment with an herbal antifungal and see if a die off reaction occurs(with your ND's approval of course)