Hello,
Welcome to HCM.
You seem to be suffering from
fungal infection of groin skin most probably tinea cruris.
Tinea cruris is a
fungal skin infection of the groin. Some types of fungi are commonly found on human skin. They usually do not harm.
You can below treatment.
You should apply plain anti fungal cream like
clotrimazole for at least 2 weeks twice daily application over your groin.
An anti-fungal oral medicine can also be taken prescribed by the doctor but if the infection is widespread or severe like terbinafine,
griseofulvin, or FLUCANAZOLE tablets.
But before that it will require clinical inspection of the local area for which you should see nearby dermatologist.
To prevent recurrence of fungal infection.
Wash your groin daily; then dry thoroughly.
Drying is perhaps the most important point.
It is easy to put on underwear when your groin is not quite dry.
The damp groin is then an ideal site for fungi to multiply. (A hairdryer is useful if you have hairy groins.)
Change underwear daily. Fungi may multiply in flakes of skin in unwashed underwear.
Wear cotton undergarments only.
Keep your separate towel.
Consult dermatologist for further advise.
Regards.