The cleanse is optional. The strict diet may seem overwelming to you when you first start to look at all of the foods people need to avoid. Just try to take it one day at a time. The diet does get easier over time as you body adjusts from the elimination of processed foods and sugars.
I would also take what ever the doctor tells you with a grain of salt and give the diet a serious and dedicated try. Many doctors don’t know much about Candida and some may even tell you it doesn’t exist. Let your body be the judge of it.