I don't think stress is the main hidden cause of Chronic Candiasis. I have studied medicine for almost 30 years in a country with a high level in this field.
Chronic stress has influence in the immune system capacity to respond to any intruder, including opportunistic pathogens such as candida, but no enough to cause this syndrome in most cases.
The fact is there are millions living with some form of stress and a non- healthy Diet that never develop this syndrome.
However, a common denominator with chronic candidiasis is heavy metal toxicity, specially mercury.