Welcome to HCM,
From your history it seems that there might be having fungal infection
to groin,vagina and thigh.
There is likely of having infection at belly button after piercing.
It has no relation with your old lesion in private parts.
Apply antibiotic cream on belly button and anti fungal cream on your private part.
Go for oral anti-fungal medicine like Flucanozole.
Keep local hygiene clean, dry and airy.
Ok and bye.