What Causes Pain In Ankle On Application Of Pressure?

Hello doctor. This morning at PT I was playing dodgeball and when I ran up to grab a ball, another cadet baseball slid into my ankle at a perpendicular angle. I heard a pop and immediately felt pain. My ankle has not swollen but it hurts for my to put much weight on it. I am trying to save a trip to the doctor s office: what happened to my ankle and how do i need to treat it?