Ran 1/2 marathon now my right ankle just below bone hurts badly when i put pressure on it standing/walking. is it just strain from running so much?

Fracture/Sprain: You could simply have an overuse injury that is similar to repetitive small sprains over a period of time, or you may have a stress fracture of the fibula, talus or calcaneus. I advise seeking out a foot and ankle specialist for x-rays, and ankle brace or a walking boot. I would not advise activity on the foot until you have x-rays taken. I hope this helps.