Hello and thanks for the query
You must go for X-ray and rule out any fracture
. This could be a acute ankle sprain or soft tissue injury
which may need immobilization of the joint for few days. Meanwhile keep the leg raised.
Do not wear weight on the ankle.
Do Ice and hot fermentation.
Wear elastic bandage
at the site.
and anti-inflammatory drug to reduce pain and swelling.
But surely you have to go for X-ray and consult your doctor for further management.
Best Wishes and have a speedy recovery.