For the past week or so my left knee has been killing me. I can't bend, kneel or lean on it. I have iced, used OTC meds, and put a brace on it. Help!

See a doctor. I the symptoms have not improved with otc medication and use of a brace, i suggest that you see a professional. They will be able to examine your knee and will probable order an x-ray to evaluate the bones. You may need an MRI to evaluate the soft tissue around the joint.
See your doctor. You have symptoms which could be serious and should see your physician. He/she will listen to you, do a physical examinarion, run some tests, and let you know what's going on.