Hello, everyone! First time posting I have been struggling with heel pain on and off for a couple of years…

Hello, everyone! First time posting I have been struggling with heel pain on and off for a couple of years now, but about three months ago, it became excruciating. I can barely walk at times. I went to the podiatrist about a month ago, and he said that my feet are very flat and gave me orthotic inserts for my shoes. Here is an issue I’m having: the orthotic inserts do not help at all, and I am unable to wear tennis shoes because I a