Ankle injury from dance?

It certainly could be a sprain. Compression with a brace or an ace wrap is good, along with ice packs for 15-20 minutes 3-4 times a day, and an anti-inflammatory medicine such as Ibuprofen (Motrin/Advil) 3-4 times a day or Naproxen (Aleve) 2 times a day. If you can elevate it, that will help to prevent and treat any swelling while the tissues heal