I am 21 y/o and live in So Cal. My AS was diagnosed 5 yrs ago. The heel pain you are suffering from sounds very familiar to me. However, my heel bothered me prior to my hip and back pain, which began at the age of 16. I believe doctors felt that I had Plantar Fascitis (inflammation of the heel). If you email me, I will be happy to suggest a few relief practices for you. In the meantime, speak to your doctor. One last thing, invest in a pair of Spenco brand insoles for your shoes. Buy the ones that have a jelly-like disk under the heel and slight arch support (THEY HELP TREMENDOUSLY!!) Take care!