And it's not going to go away soon, tho I wish it would.
See if your doc or podiatrist has some co-flex disposable wrap and maybe some pre-wrap that you can use to help keep things together. Then keep off it as much as you can with some ice compresses on it if you can stand them.
I agree with everyone that you should see either an orthopod or podiatrist to help check and make sure there is really no more damage than a 'sprain'. Sprains are bad enough. If it's worse, well..nuf said. Best to be cautious with this stuff or it could get worse.
That uneven ground can be the undoing of us all! Get well FAST! - j