What Causes Itchiness In The Groin , Scrotum And Thighs?

Hi, I have a itchy groin area, i.e. between my scrotum and thighs.The area has also gone darker after this itchiness started. The itch is very mild during the day but often gets unbearable at night. Also, the head of my penis gets a white coating daily even though I was it regularly. There is a bit of a foul odor too. I have used anit-fungals but not got any relief. Would appreciate if you could help