Hullo. I feel your pain, I was a volleyball player who had 2 nasty sprains on the same ankle that resulted in broken ligaments, and pretty much quit playing because of them. I'm in with the others, consult the doc or a PT first. What helped me get my ankles in shape was a flat leg press machine, tho: I'd set it up to a really light weight (30-35 kg) and do exercises for calves (legs straight, push in and out only with your calves). I took great care that both my ankles were symmetrically loaded. Now I gradually worked up to 110 kg on that exercise (I can do more. But don't want to!

) and my ankle has completely healed!
Because of the weakened ligaments, I still sprain it here and there while running in the country, but I shape it back up in a month - month and a half using the described exercise. Also, I take glucosamine supplements during the recovery and I'll swear by them any day.
BUT, make sure to consult your doc first!