It sounds like if you for a knee brace you might want to go with the ones offensive lineman use. As far as I know they're the best for relieving knee pain and preventing further injury.

As far as slowing down, it was tough for me as well because I used to play football and that is a very fast and intense game. I wanted to throw the ball incredibley hard and fast when I started but I learned that I had to slow down and roll the ball and let it do the work for me.

I had an arthroscopy done on my left knee, on my plica ligament (unrelated to the patella), just over a year ago. I was walking in a few days, and running in a few weeks. Arthroscopic surgery is the way to go if you want it fixed for a long duration. A brace could also be good for minimizing damage for now.