Please call me to discuss things in detail..

Mostly Sketcher  or nike company shoe do wonders but are expensive . So u can buy as per your comfort and convenience after taking trial in person and not online shopping . It should have   soft and memory foam sole. To keep pressure off your feet. If u cannot use sport shoe to work then  you need to buy a silicon gel  sole  or memory foam sole which you can put in formal shoe and use it . You also  need proper size shoe ..which has good amount of room for your feet. And comfortable.

Decrease your walking time and distance Change shoes and try front open footwear

Looks like you are doing right things. May require some tests and more history from your side.