do you do the XC season to stay in shape? I'm a high jumper also (it's the best! 😀 ) and I considered doing XC, but decided to stick with field hockey as a better way to maintain explosiveness and stay in shape as well. running too much long distance over time can convert fast twitch muscle fibers…. not too mention being hard on your ankle!
for ankle problems i usually do basic balance excercises like standing on one bent leg on a trampoline or similar unstable surface for timed sets. i hope it gets better!