Hello,
I cannot confirm anything without examination but it can be tinea cruris. Wash your groin daily and then dry thoroughly by pat drying, not rubbing. A hairdryer is useful if you have hairy groins. The damp groin is an ideal site for fungi to multiply. Also wear cotton underwear and change them twice a day and do not share other people’s towels. Application of local antifungal cream(terbinafine, clotrimazole, econazole, ketoconazole, miconazole) and oral antifungal drugs are the mainstay of treatment.
Most cases of fungal infections respond to over-the-counter products, which contain any of several basic ingredients: miconazole, tolnaftate, terbinafine,ketaconazole and clotrimazole. You can consult a pharmacist and get any cream or lotion containing these ingredients. Some of them are Lamisil, Monistat derm, Mycelex, and Nizoral. If the symptoms persist then oral antifungals may be needed.
I hope it helps. Take care and please do keep me posted in case you have any additional doubts. Kind regards.