Thanks for asking me to reply.
Most ideal thing to do is to visit an ortho surgeon who can evaluate your ankle and order an xray of necessary. This will help determine if you have any bony injuries or just a simple sprain.
From your side avoid bearing weight on the leg. Ice the swelling, and keep your feet elevated on a stool. The ortho surgeon can also prescribe meds for you. I am not able to prescribe meds as Practo prohibits me from doing so. Apply a crepe bandage firmly without being right. This compression will help reduce the swelling quickly.