I can understand your concern.
it looks like a fungal infection called pityriasis.
but for the confirmation of the diagnosis, i would suggest you consult a dermatologist in person.
once a diagnosis is established, the treatment can be started.
as of now, use a mild soap to bathe, and apply a anti fungal powder like candid dusting powder everyday. wear clean and dry clothes and take bath twice a day.
do not delay your visit to dermatologist.
Dr. Anil kumar jain.