Hi there...from the description you have given it looks you might be suffering from scrotal dermatitis or tinea incognito or topical steroid induced dermatitis. But it will need a complete and thorough examination. And few test like KOH examination if any scales are present. If you were visiting general physician or pharmacist, they would have given you steroids, which will only aggrevate the lesions. So kindly consult a dermatologist. They will be of better help to you. Till then you should use only lukewarm water with little salt in it to wash your genitals. Do not use any other than those prescribed by the dermatologist and do not apply any antiseptics like dettol.