You have not mentioned how you arrived at the diagnosis of candida infection of the oesophagus. You should be aware that fungi and bacteria are all around us in the environment, and a lot of them, including candida and a large number of bacteria, are a part of the normal flora of our body - in the mouth, intestines, skin, vagina, etc.
The body has defence mechanisms in place not to let these commensals become pathogens and cause disease. However, in some situations, these organisms that form a part of the normal human flora, can become opportunistic pathogens, but these situations are seen in hospitalised patients, and are extremely rare in out-patients.
In your case, please do not worry too much. There is no role of starting any treatment without a definitive diagnosis as most of these drugs have side effects and cannot be used without medical supervision. A visit to a physician for a physical examination, and if required an endoscopy, will remove all your doubts.