Others have already given you all the medical advice I could, so all I can do is wish you better soon. :)
ouch that sucks. i know what its like to injure ur leg
I have weak ankles so this has happened to me many times XD I usually just stay off my feet for a few days if I can and it's fine
I'd suggest to do what Nera said. When I sprained mine, I didn't do that and it was torture. Make sure you don't walk or do anything on it on it either without it wrapped because the swelling will get worse and even when it's wrapped, make sure you keep your weight off it.
First apply ice to it, that way it won't swell up (though, if you didn't do this as soon as you sprained it, it'll take longer to heal, and will hurt more), then wrap it up with a bandage. It'll be better within a week or so. :)
Just keep weight off of it the best you can and slowly move it to stretch the muscles. It should feel better in no longer then 3 days.
Thanks for the help :)