Hi, I Am A 28yr Old Female Baker And Last

Hi, I am a 28yr old female baker and last night I hit the inner side of my left knee on some metal tin lids. The pain of the initial hit was intense and I had to stop working and settle myself, it felt like when you bump your "Funny Bone" but much stronger and lasted longer. During the course of my day I have had only slight pain while walking, but when I raise up from a crouching or sitting position I cannot put my weight on my left as the pain is again pretty intense. It is bruised and a little swollen. A few years ago I was diagnosed with degenerative cartelage in my knees.
I was wondering if the pain is just from the bruising or could I have damaged my knee?
From Karrie