Hi, thanks for writing to HCM.
Based on the description, I suspect that you could be suffering from Retrocalcaneal bursitis
(inflammation of bursa at the back of heel).
The initial treatment of this condition involves
* avoiding activities that cause pain
* taking NSAID's like Advil
* Icing the heel several times a day
* physical therapy
to improve flexibility and strength around the ankle
* Over-the-counter or custom heel wedges may help to decrease the stress
placed on the attachment of the Achilles tendon and the associated bursa.
If these interventions are ineffective, then some health care providers may inject a small amount of steroids
into the bursa.
Very rarely, surgery may be necessary to remove the inflamed bursa.
Hope this information is helpful. Good day