Nystatin is better than Diflucan to take care of systemic cases of candida. Diflucan is real good when you only have a vaginal infection. Natural antifungal like graprefruit seed extract and garlic are (in my opinion) even better than Nystatin.
Die-off will follow DIflucan (or any other antifungal). But die-off can be controlled with small dosage and with antioxydants. Read about it here:
Most people know that magnesium and vit. B are essential supplements, but few realize the benefit of antioxydants. YOu have mentioned itchy symptoms. If you mean itchy skin then, you have a deficiency in Zinc and selenium.http://curezone.com/blogs/m.asp?f=308&i=16
Die-off is all about healing too fast. Go slowly with antifungals and expect a flare-up after cheating (this is why it becomes so easy to follow this drastic diet, time after time, you get to flare-up if you cheat).