Bill, I feel your pain...literally.
Have the same thing. Went to a sports injury specialist who as a first course of action referred me to a physio. After about 2 weeks of daily stretching, quads, hip muscles, calf, glutes it felt much much better...almost like new. No exercise at all during this time. Got back on the bike yesterday at physio's endorsement and did about 7 miles. Have general soreness in the knee area now and expect the patellar pain will return if I go out again.

I had the feeling this could happen so while dissappointed...I'm not completely surprised. Just interested in what the physio will say next. I'm guessing I'll be going back to the specialist for the next step...not sure what that is. I intend to keep up the stretching though.