To cure a Candida infestation, whether it’s on the skin or otherwise, you’ll need to be on the diet and take antifungals as well as probiotics. How long it takes varies from person to person depending on how long the infestation has lasted and how bad it has grown over time.
You don’t need to literally start all over again, just continue as if you didn’t screw up. This will simply add to the length of time that it takes to cure your infestation. Of course it’s also possible that your symptoms will grow worse for a while.