Thanks for the query,
You might have developed fungal infection
called as Tinea cruris
The area of groin is prone to develop these infections.
Itch guard or other OTC drugs will not help you.
Treatment is with oral antifungals as well as with topical antifungals.
Various anti fungal powders like candid
These can help reduce the moisture as well as control the infection.
Please meet a dermatologist
for exact diagnosis.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you good health,