Pes Anserine Tendinopathy is further down on the inside of the knee, not near the kneecap. I know, I've got it, though it's impossible to tell if it's tendinopathy or bursitis.
Most probably your saddle is too low. Yes, you've been doing this for a long time and you probably did overdo it a bit, which started this happening. Usually pain there is from the kneecap not tracking correctly. So raise your saddle 1/2 cm. Sitting on the saddle in your normal position, with your knee locked out straight, your shod heel should almost, but not quite touch the pedal at 6 o'clock. Then start a twice-a-day stretching program with particular attention to the hamstrings. Also start doing straight-legged high kicks a couple of times a day. Just kick as high as you can with your leg straight, several reps with one leg, then the other. If you can, don't pedicab for a few days. Instead ride a regular bike very easily, no more than 1/2 hour at a time. You can also take 600 mg ibuprofen twice a day. Should have it cleared up in a week.