Plantar fascitis. Take for it to heal?

I had plantar fascitis in my right heel, it occured when I was wearing a very flat chappal on A very Rocky road, a pointed stone just got to my heel and i was limping immediately. The pain subsided and reoccured after few weeks and it became extremely difficult for me to walk, went to doc, told it was plantar fascitis, took steroid since pain was worse and painkillers were doing no good. But even after that was not completely well, got xray done and plantar fascitis was gone but still had pain. Continued with homeopathy medicines, cold therapy and exercises, and pain was subsiding. For few days,had extensive walk,missed exrecises and cold therapy, pain got back again immensely. Please tell me what is causing the pain and how to get rid of it? Is walking still the cause behind pain? How long does it actually take for it to heal?