I am having severe knee pain. I can hardly put weight on it. I injured it on Monday stepping up into a bus with my right leg. It seemed to get better right away. I had some pain on and off after that. But, it seemed to be doing well earlier today. I have been doing alot of stepping up and down in and out of garage and front porch. Today, when I stepped out on porch, just one step down, I was in severe sharp pain. I wwalked over to bench and then couldn t get up for pain. My Knee got better but was somewhat numb. but i was able to get up stairs. I drove to my son s house and walked around ok. But when I went to sit down on toilet severe pain came again I have been unable to walk very far since . I can sit but severe pain when trying to stand up and walk. How do I know if I tore something or it is more like a sprain? treatment?