It's highly likely that you are suffering from a fungal skin infection. What you could do at your level is: change undergarments twice a day, avoid wearing tight jeans or pants etc. But this is only a part of the treatment . You will need oral medicines for which you need to visit a dermatologist so that the doctor can examine you and treat you accordingly. So visit one. You will benefit. DO NOT use creams suggested by friends or family or pharmacists. It can only worsen the situation.