Welcome to HealthcareMagic forum,
Seems like you are having a fungal infection
around your groins .keep the area clean and apply anti fungal cream like ketoconazole
or cotriamozole locally for atleast 6 wks .If sever you can take oral anti fungal also.if you sweat a lot then apply anti fungal powder too.Dont feel shy showing to a dermatologist
,he is going to help you only.