I have horrible ankles... I have broken my ankle twice (no way to walk on it and the pain did not go away till I had it in a cast), sprain it at least once a month if not more and twist it weekly. Ice it and keep it elevated when possible, even if you can put it on a small box or step stool under your desk that helps.
Ice for 20 mins then take a little break so skin warms up again then ice again, this will help with swelling. Ice after any activity, such as a lot of walking, driving if using that foot, or anything that seems to make it swell again.
In the next day or two if you are still a little sore HEAT it BEFORE the activity, can use a warm towel or heating pad for 20 mins, this will help relax the muscles and lossen the tissue to be used during an activity (like sport, walking and so on).
If it seems to be getting better then keep up what you are doing. If it does not hurt when you walk on it and heals in a week then you should be good to go :) If it seems to be getting worse or not improving in a few days then it might be something to go to the doctors but it seems you are doing great at taking care of it at home.