Thanks for posting your query.
From description , it seems muscular/ ligamentous strain at your lower calf and behind the ankle.
It might occurs due to continous stress
to that area.
I suggest you to consult an orthopaedician nearby for a detailed examination.
Meanwhile I advice you to give rest to your calf and ankle. Avoid sport activite for some days.
Always warm up and stretch your muscles before starting sport activity.
You can take anti-inflammatory drug like motrin
to reduce pain and inflammation after consulting your doctor.
Wishing you good health.
Dr saurabh Guptaj