Bacteria love to feed on the sweat from your feet. A daily antibacterial soap foot wash or soaking in brewed tea or white vinegar will help to curb the bacteria.
Wash your feet and change your socks a few times a day. There are many foot powders available to prevent foot sweating and that should cut down the odor considerabley.
Change socks and shoes 2-3 times a day. Wash your feet 3 times a day. there are also medicated powders that you can get at a drug store. Also buy well ventilated shoes