I had very similar pain to what you are describing. I used a raquetball to smash the area just above my knee on my quads. It hurt like hell, but after a day or two of 2-3 minutes 2-3 times a day, the pain was almost completely gone. I started including some form of quad/hip mob (usually smashing w a raquetball or pvc roller) to feed slack into the knee. Seems to work for me. Good luck!