Bottom of feet turn white when wet….not a callous

After using a metal foot file tool at home, certain parts of the bottom of my feet turn white and the area is slightly raised when they are wet, mainly the skin that was treated with the file. No itching, burning or any other symptoms. I’m not sure what this is. I’ve researched online and found others with the same problem, but no one has an answer. When feet are dry they look fine, just a slight discolouration, a little darker than the rest of the skin on the feet. I’ve tried otc anti fungal cream, Vicks Vapor rub and currently trying hydrogen peroxide and vinegar soaks. Nothing seems to be working.
What is this and how do I treat it. Have a dr.s appointment in a few weeks, but just wondering if anyone has had this and how I can treat it. Thanks!