I have plantar fasciitis and it came on all of a sudden in pretty much the same area you described, left side of
heel of right foot. It is now on my left
heel, in right side of
heel. Have you been on your feet more recently? Increased your exercise? Mine came on after increasing exercise. Currently, I am stretching it at least once per day, doing some strengthening exercises 2-3 times per week. I also apply ice 1 time per day for about 15 minutes when I need to.