Kate,
I'm so sorry for you!
Be careful, as has been said with the constriction, and there is some controversy with ice.
While ice itself is a no no. Cool is not necessarily so bad. It's to keep the swelling down.
So, if you can say, dampen a towel, and put it in the freezer, then, insulate it with another smaller towel, and wrap lightly with that.

I'm not saying to ICE your ankle, but gently cool it.
I've done this sort of thing many times, broken toes, the TOS, and ankles, they haveto be cooled, that's why the towel.
If you have a "icepack" or ice bag, use a towel, so it just "cools" the ankle.
keep the swelling down.

And, give it some "Tincture of time".
Stay off it for a while.

I feel so badly for you.

Please, take good care!

Pete