Hi there OS,
I'm new to this (12 jumps), but thought I'd drop you a line anyway
The most difficult part in landing was my height perception and appreciation for my running speed. Usually we had reasonable wind speeds to land into, but I had to think about it all over again (a very good thing) when we started landing when the winds had dropped off.
When I was first guided in via radio, the standard procedure was for the instructor to relay "stand by, stand by, 3 - 2 - 1, flare, flare flare". So at the third instruction to flare, my toggles would be pulled all the way down. At first, I found this difficult as I varied between upright landings or the standard PLF (falling over and feeling silly ). Then, once it was under my own control, I experimented a bit to find the approach that worked for me. I watched a few landings performed by the military, other students, club jumpers and tandem jumpers, which really helped as you can then start to attribute their physical actions to the response from their 'chute. I'm a slow learner, so I spent some time observing and I'm glad that I did.
What works best for me is to half-flare at around 10ft, then complete the action with a slight delay. The outcome for me is that my descent is slowed and I still travel forward (but not much) before executing an upright landing. This works almost all of the time. My point is that even though there is a right way to land, you have to approach the action in a way that works with your style.
Also, have you practiced your PLFs even when not jumping? This helps as well, I do it at home just to remember the action/position, which helps reinforce your confidence that you can walk away from a less than ideal landing.
Have you researched reinforced or suitable footwear to help support your ankles? It may be worth speaking to a physiotherapist or trained sports therapist, since their experience with related injuries could help injury prevention. I'm a sports massage therapist, but my course didn't cover skydiving
So, that's my very inexpert and beginners' contribution, I'm sure you've probably considered all of this before! I really hope that you find a way to resolve this, it would be sad to have to give it up!
Eugene x