What Could Prolonged Bruise On Knee With Protruding Fibular Bone Indicate?

I am a 21 year old male for the past couple weeks it felt as if there was a bruise on the side of my knee. Time went on and pain still occurred. I recently hit the same spot on my bookshelf and figured it was a bruise. Time has went by and never went away. Upon further inspection I noticed it wasn't my knee, but the head of my fibular bone on my right knee. It's really poking out with a lot of pain associated with movement. I don't have a lot of medical history,but I've always been pretty skinny and have had joint pains. Ganglion cyst in my wrist in elementary. In high school they diagnosed me with arthritis. I don't mean to second judge doctors opinion but feel that they were to quick to diagnose. I don't have any insurance! Please help!!!!!