left heel hurts

This is the 4th day that my heel is in pain when I put pressure while I stand or walk. If I walk on my toes, it does not hurt. So I have been walking super slow which is so hard for me to do. I have an ankle brace on and I'm using the arch support. I guess it just needs time to heal. Last week, I over worked my heel by running too much on the treadmill without resting between days. I brought in a stool to work so I can elevate my foot. I talked to the nurse at Kaiser and she gave me some tips. If the pain gets worse in a few days, I'm going to the doctor.