Suggest Remedy For Swelling And Pain In Knee

I started having knee pain about two weeks ago. It causes the most pain when I put any weight on it. If I am sitting or lying down it does not hurt much at all. It is swollen, so I have been putting ice on it when I get the chance. I have also tried ibuprofen 800s a couple time a day. My job requires both walking and sitting for periods of time. I am a teacher who travels from school to school. It seems to be getting worse every day. I have also tried wearing a knee brace to help stabilize. About two months ago, I had 3 bulging disc in my lower back. I went to therapy and it got better, but it seems like this knee pain is starting to cause a bit of lower back pain. I am afraid to go back to square one with my back. I have not had any apparent falls or anything that brought either of these conditions on. What can I do to help my situation?