Socks: wear merino wool socks or other very good drywicking socks (check google. it's pricier but worth investment). also bamboo socks have good reputation and are cheaper.
Shoes: geox, or make sure it’s breathable shoes like leather
Insoles: Cedar wooden soles!! this is a must!
Then ask yourself if this is a bacterial overgrowth, fungus or sweat problem. Best to always check with a dermatologist!! Go to one!!!
Bacterial overgrowth: You can check if fucidin lotion (note it’s a medicine, don’t overuse) can help you. Sometimes anti acne lotion can help such as clindamycine or benzac 10% . The bacterias causing zits can sometimes be same bacetrias causing smell. Do please check a dermatologist before proceeding with these lotions. You can apply 3 times in day for a month, and changing socks everytime.
Fungus: check for topical antifungus like clotrimazole . Again, check with dermatologist.
Sweat: Apply strong anti perpirant (15–20% aluminium chloride), if that doesn't work check into buying an iontophoresis machine and combining with glycopyronium bromide medicine, if that doesn't help there's a surgery only if you have plantar hyperhidrosis (it's called lumbar sympathetomy)
ALWAYS WASH FEET IN MORNING AND NIGHT WITH HIBISCRUB (it has chlorexhidine gluconate 4 %. it's bactericide for hours)
While I don't know if this would work on feet, I do know that excessive sweating underarms can be stopped with Botox injections. Have you talked to a dermatologist about options?