Trying using your fingers to massage the tops and sides of your feet. Your peroneals could be tight which is causing the outside of your ankle to become unstable(peroneals help with eversion of the foot). Try mobilizing your shins, calves and ankles and see if that helps. Use the search function and look for videos with the words “heel cords, lower leg bits, ankles” etc. If you need help finding a video let me know.