To what extent is my ankle injured???? Urgent?

Hi i suffered an ankle injury while playing football yesterday.. and while trying to change direction i twisted my left ankle inwards and i heard a snap in my ankle simultaneously. It was very painful and my ankle had some swelling, but not much. I can put weight on it when the ankle is placed flat on the floor, but when trying to rotate even slightly it hurts alot.. can you please help to diagnose my problem, as i need to know asap whether its something wrong with the ligaments, as i have a very important football trial soon and need to know how long it will take to heal.. thanks