You probably sprained it. Is it swelling up? Is it showing any bruising? I did the same thing last December. I stepped half off the edge of my sidewalk and rolled my ankle to the inside. It pulled the muscles and tendons farther than they are meant to go and it hurts! My ankle and foot swelled a lot, and bruised something terrible. I could barely walk on it, but I did. I kept it up as often as I could and kept ice on it for the first few days. I wish I had gone to a Dr about it but it was 3 days before Christmas and we had company and dinner to do and things going on, so I didnt. It still bothers me nearly a year later. I cant cross my ankles without pain, and cant stand on tip toes on that foot, and it seems to twist and hurt easier than before so it keeps re-injuring it. I wonder if it was broken and I should have had more done to make it heal properly. I worry that in my later years it will be the foot that doesnt hold me up and work right and I may have caused a crippling problem when I could have avoided it if Id gone to the Dr sooner. So if you can, see your Dr. If you cant or dont want to, at least ice it and keep it elevated when possible. Take ibruprofen if you can to help with inflamation that causes swelling. Hope it heals better than mine did. Want to see pictures of mine? I will send them if you private message me your email address.. Yes I take pictures of fat feet ,,lol