wow--it seems like you've had quite a time of it. I agree with camama--if your knee is still swollen and black and blue today, I would head over to urgent care today. Then follow-up with your rheumy tomorrow.
With respect to the interview, my personal opinion is that it would be better to walk in with a limp and a cane, then with just a limp. The cane kind of legitimizes the limp, kwim? If I were interviewing someone, I don't think that a walking device and/or limp would affect my decision either way, unless I was interviewing someone for a construction job.
In any case, I hope you feel better soon and that things start going super for you. good luck on your job interview!