You definitely need to take some time out to rest it. Unfortunately knees are one of those things that take a long time to heal.
I just got over a case of Patellofemoral Pain Syndrome caused by running too much without training my supporting muscles.
It took about 3 weeks for the pain to go and that's with me doing as little as possible with my knee. No walks longer than 15 mins and lots of stretching and strengthening exercises.
A physiotherapist will help a lot, my Doctor just told me to stop running. My physio gave me more practical advice and a programme of exercises.