From personal experience how long does it take an ankle sprain taken to get better and heal?

6 to 12 weeks. There are 3 grades of ankle sprains. I typically tell my patients that a sprain bad enough to take you to the doctor or ed will take 6 to 12 weeks to fully resolve.
About 6 weeks. Wide variation in severity of sprains- depending on how much of the ligament(s) tear. Rule of thumb is that the ligament will be weaker than normal for at least 6 weeks, even if pain resolves- so wear a brace or avoid activities at high risk for turning the ankle (basketball, tennis, soccer are a few) if pain persists, you have locking, or recurrent instability- get it checked.