Heel spur and overweight
Heel spur/plantar fasciitis is a real stress-related injury, and one of the reasons for this stress can be overweight of the patient. Should you suffer from overweight, try to reduce this, the excessive weight puts a constant strain on the heel. Even if the overweight is not the direct cause, loosing weight will still help in curing the heelpain.
In short, try to put yourself on a diet, or try some exercise/sport (and make sure to choose a sport that does not put further strain on the heel).