Fungus or yeast infection....common around skin folds like thighs and genitals.. avoid sweating, sharing clothes,towels and soap.. specific medicine required depends on the severity.. for detailed prescription do direct online consultation.

If i look at the picture, i understand that you have been applying inappropriate creams for very long.  Please see a qualified dermatologist near you at the earliest.  You need to be treated immediately for fungal infection, as well as to prevent bacterial infection of the wound.  Warm regards,  Dr Govind Suresh Mittal,  Therapeia skin hair and ENT centre, Bengaluru.