Why Is My Ankle Paining?

On Monday, I woke up and walked to the bathroom, and my ankle hurt really bad. I didn't think anything of it because I've had pain before. Then on Tuesday, I woke up and my ankle was so swollen, you couldn't even see that I had an ankle bone. The pain was still there, however I have a high pain tolerance, so I just got use to it and continued with my day. It is still swollen and it is Thursday. I have been icing it which has helped some, but the swelling comes back after walking on it. I can still move my ankle just fine. I also have swelling under my arch of my foot. It also hurts to touch my ankle and the bottom of my foot. I broke my ankle 6 years ago, and was thinking maybe it's scar tissue breaking up, but it has never hurt this bad or been swollen for this long. What is going on with my foot?