It sounds like you may have a common, easily treatable fungal infection triggered by moisture and friction. For mild cases, over-the-counter topical antifungal creams containing clotrimazole, miconazole, or terbinafine are highly effective. Apply the cream to the clean, dry affected area once or twice daily for one to two weeks. Oral antifungal tablets, such as fluconazole, can also treat this but typically require a doctor's prescription. To aid recovery, keep the area dry, wear loose-fitting cotton underwear, and take regular breaks from sitting. If the infection does not improve after a week of cream application, please consult a healthcare professional for a personalized evaluation.