What causes burning feet and tiredness?

So many things: Possibilities include a neuroma, nerve entrapment, diabetic or peripheral neuropathy, athletes foot, tarsal tunnel syndrome and a host of other things. Tiredness could indicate a lack of support in your shoes and standing too much. Consider an arch support. You are 66, so you probably have medicare. Consult a podiatrist.

Neuropathy: Could be a variety of things. Most likely, it's neuropathy "nerve - disease" which can be attributable to a variety of factors. Things like diabetes, low back issues, vitamin deficiencies, etc can all cause burning feet. I would recommend seeing a podiatrist or neurologist for further workup.

See below: Overuse syndrome, lack of foot support, entrapment of a nerve.