I sprained my ankle two, almost 3 weeks ago (cont.)?

Well the swelling hasn't went down at all. The bruising is doing nothing but getting worse. I can walk on my foot but it hurts really bad. After about 10 minutes on it. My foot is in so much pain I want to sit down and sleep the pain off. I just stood up and my ankle felt all weird I took a step and it felt like something was moving inside my foot like it moved. What should I do?