I feel your frustration, it drives me a little nuts not knowing 100% what is what. Another thing to take into consideration is that die-off can also be the effects of detoxifying your body.
I read that even people that aren’t suffering from candida overgrowth go through this when they cut out processed foods.
I personally had an extremely bad diet where I only ate take out day after day and never restricted what I ate. All that food comes with additives and chemicals that I’m sure come with withdrawal symptoms like any other chemical.