Walked 13 miles sun & had pain/swelling in my left ankle since that evening. i can walk on it but not normally. pain is mostly located on outer part?

Walking like that --: Will cause anyone such symptoms. If you don't work out like this regularly, then pain/swelling would probably be, not normal, but expected. Give it a few days to rest, massage, take pain meds, regular exercises to prevent stiffness, icing/heat all would be helpful to give you relief. Muscle relaxers would also help. See your pcp/orthopod.