smelly feet and smelly socks / shoes are caused by a fungal bacteria.
you can buy very very good anti fungal creams and sprays in the chemist or supermarket nowadays (or look for them online).
you are wearing the right kind of socks (cotton).
you should be washing and drying your feet in the morning, then spray them with antifungal spray, then let them dry, then spray your shoes, let them dry, then go to work, probably change socks halfway your day, when you come home, wash your feet and dry them, put antifungal cream on, in between your toes and everywhere, let it dry, then walk barefeet until you go to sleep. spray your shoes before you go to sleep.
ps do this for at least two weeks straight.
it will really eliminate your smelly feet and your worries.