Thanks for sharing man. And great advice.I know the feel dude. A couple of years ago i sliced my quads tendon off my kneecap after a fall on some oyster shells.. contaminated wound, 2 operations, the works. Was so bad, in my first physio session I couldn't turn the pedals over on an exercise bike at resistance level 0 and my leg totally atrophied. It got better slowly, I got back to training and within 12 months of the accident I'd run a marathon and got my squat up over 2xBW.
So, don't worry it will all come back quickly when you can train properly again. In the meantime just listen to your physio (hopefully you have a good one) and rehab as effectively as you can.
Since its your ankle, you can probably do iso holds for your quads and hammies, maybe even leg exts and stuff. Also, like Tosa said do single leg stuff as it helps the neural pathways on both sides (this has been scientifically proven). Don't go overboard though and give yourself an imbalance. Swimming for cardio so you recover better and can smash it hard when you're healed up.
Its gonna be painful and its gonna suck when you're doing "stupid" shit like sets of 10 toe raises with no weight but you've just gotta stay focussed on getting better; not get impatient and give yourself a chronic issue.
I got in to a really good specialist through family friends. Gives me confidence that my physio is the physio for a professional rugby team in the highest league.