Thanks for posting your query.
It might be ankle sprain
Without X-ray, it is difficult to differentiate a fracture from others. I suggest you to consult an orthopaedician nearby for a detailed examination. You may get the X-ray of the area affected under his/her guidance.
In the interim, ice the affected area and take anti-inflammatory drug like mortin to reduce pain and inflammation. Avoid putting weight and rest well.
Dr Saurabh Gupta