Everyone here means different things when they say anti-candida diet. :) My diet allowed meat, fish, fermented foods and condiments and spices, and only cut out dairy, sugar, wheat and fruit. Thus I was able to keep up my energy okay. Are you allowing yourself protein and healthy fats such as olive oil and flax seed?
The other thing that can help is cleasning your body of the die-off from the Nystatin. Drinking more water, a series of colonics and/or deep enemas, hotbaths+niacin to sweat, and taking psyllium with Bentonite clay will all help with that.