What Causes Sweating Between Thighs With Bad Odor?

hi I have a problem with sweating between my thighs. It also has a distubing odor and a white residue is always present. I dont know what is and it is quite bothersome. I shower and within 30 minutes it is back again. I havent seen a dr as I am very embarassed. I am 26 ,5`6 and 210lbs. So I am overweight but I dont feel this is the problem entirley.