It’s not too late to sort things out. It depends on whether there is any joint stiffness, pain, scarring in the ligament, flat feet or just impairment of your proprioceptive system.
If it is just the latter you could start by practising standing on one leg whenever you get a chance. It would probably be best to have it assessed by a chartered physiotherapist who will be able to advise you on how best to break the cycle.