Candida is ALL about how toxic your body IS and.. as long as toxins are passing by your blood to get expelled out, you WILL have candida. Fungus grows on toxic waste.
To me it is not so alarming. You know where you stand. Your body is EFFECTIVELY getting rid of toxins it is just a matter of keeping at it. Your metabolism can only get rid of a bit of toxic waste at a time. Otherwise the blood cells will expode and you will die. So healing candida is a long term goal.
Your main concern seems to be regarding weight loss. Ask you Doc to get your thyroid checked and treat it so your defense system works better. Weight loss is due to a- poor assimilation (poor liver function - dirty bowels, which you seem to have addressed)
b- thyroid malfunction
I would ask my doctor for Nystatin over Diflucan (not from experience I personally only used natural antifungals: GSE, garlicg and oregano Oil) but from the feed backs here Nystatin seems to work better than Diflucan.