Earlier this year I fell down and wacked the side of my foot on the pedal. My podiatrist said it was nerve damage, not broken bone.
You can encourage healing by controlling inflammation. You do that by avoiding refined foods. I eat a lot of fruit. Exercise will improve circulation, as will gentle heat.
This is just a guess, but it sounds like one or more nerves got cut in the operation. Sometimes they heal, sometimes they don't. Good luck.