Ankle Problem

I twisted my ankle really bad about a year ago.  I'm a newbie and have only been running and swimming for about a month and half.  I haven't had any problems with it until after a 2 mile run I did yesterday afternoon.  This morning I woke up and it was very sore on the outside beneath my ankle bone and up along the back where my achilles is.  It is not bad enough to warrant a trip to the doctor yet.  I was wondering if maybe I should where an ankle brace for awhile when I run.  Also, what type of exercises do you recommend to strengthen the ankle?

Thanks,

Jen