Welcome to HCM,
The history and symptoms are suggesting me that you may be having fungal infection
. The fungus are the normal comensals of the genitals which is kept under control by the helpful bacteria, whenever there is a imbalance between them it will leads to multiplication of fungus and the produces the symptoms which you are having.
The fungus tends to survive for longer period of time in a wet area. So you can be having fungal infection and i would suggest you to follow
2.Keep the area dry and clean