I agree with you! Often yeast showing up externally could be a part of Candida overgrowth and should be treated within, not with creams. I would say that prolonged water fasting could be best cure as your yeast wouldn't be fed by sugar and also body feeds itself on anything it doesn't want. After the fasting avoid sugar, whole grains should be OK. There are also natural herbal products you can use, just Google the web.
Do you have problems digesting soem of the food or do you get bloated? That might tell you if it is the case.