I had bad fall once that caused both my foot twisted and torn ligaments that unable me to walk for 3 months. I was bed ridden and physically immobile temporarily. Once recovered I had to start walking and drive to work, my orthopedics doctor suggested me to get the Aeroshoe. It is a special shoe that has air under sole to cushion the feet from pressing on hard surface. I am sure you can find them in the medical store. Good luck.
At one point I worked for a Podiatrist and 2 orthopedic surgeons at a foot & ankle clinic and the cause could be one of a few things, but it could be plantar fasciitis which causes heel pain due to a heel spur or it could be Achilles tendinitis. Anyway, take anti-inflammatory meds such as Ibuprofen to reduce swelling which can cause throbbing, modify your shoe wear or wear a heel cup, and also do the iced water bottle trick: freeze a full water bottle and roll your heel over it for about 20 minutes. But, to truly know what's best for you, I'd go see a Podiatrist!
Agree with the above
What Chipmunk said
Go back to the doctor