If there are still problems six months ago, this guarantees that the ankle muscles do not have the coordination to hold the ankle stable. With the problem lasting this long, there could also be additional damage to other areas. If there are additional painful areas, I would highly suggest getting it assessed by a physician or doctor of PT if you are in an area with direct access to PT treatments.
Your healing depends on the severity of the injury. Usually, the ankle takes a while due to its weight bearing nature. Have you been doing physical therapy also? PT can help heal faster. Unless an evaluation is done, it’s hard to answer the question.
Typical ankle injuries will heal in 4-6 weeks. It is not unusual for the ankle to be painful and swollen for longer periods, but physical therapy should help to address the injury and functional deficits. See a physical therapist that is trained in the McKenzie method of diagnosis and treatment (MDT).
There are no magic tricks to hasten the process. All you can do is be sure you're very compliant with your doctor's orders and your physical therapy. Find a PT that uses class IV Laser and vibration therapy. And if you smoke...stop.