Suggest Treatment For Painful And Swollen Ankle

Hi, I injured my ankle over 3 years ago however i did not seek medical advice at the time despite my ankle being more than twice its usual size and bein unable to walk on it. Ever since i constantly have problems whereby the pain is so bad i am unable to walk or there is a dull ache that will not go away for days despite resting my ankle. I have been to my GP about a year ago who gave me some anti-inflammatries which did not help in any way. What do you suggest?