I know this sounds almost ridiculous, but get a pedicure. I have terrible problems with my heels, and my Dr. sent me to get a pedicure. I go every three weeks, in between times I scrape my heels with a foot file, and I use a heavy moisturizer every night to bed. If I get cracks in the heels, I put a drop or two of crazy glue in the crack to close it. I also wear an orthotic insole. I find that I get this worse in the spring and summer months because of wearing thongs.
Whatever works for you, I wish you luck. I know how frustruating heel pain can be.
Tracy