What Is The Calice On My Heel?

I have a calice (sp??) on the heel of my right foot. It hurts extremely bad when I put my shoe on or stand on it for long periods of time. I have no clue what it could be. I have put lotions, scrubs, cremes, gotten pedicures, nothing cures it. The area around it is tender as well. Any ideas who I should go see or what it could be?