49 years old here, and I've had to deal with some knee issues now and then.
1. Listen to your body. Jonesing to play shouldn't count as much to anybody as possibly inuring yourself badly. When something hurts, lay off stressing it for a while. Ice as frequently as possible to reduce swelling and see if you can identify the cause. (I had a hamstring issue I tracked to how I was sitting at work - eliminated the cause and it got better.)
2. Video your drive and see what exactly you're putting your knee through. The best technique for the plant leg is rotating on the heel, not the toe, with the leg straight. This minimizes torque on the knee.
3. Try a brace to minimize knee movement.
4. Use stairs much? Try taking the elevator for a while. Using stairs, especially going downstairs, puts as much as 5x your weight strain on your knees with each step. I resisted this since stairs at work were part of my incidental exercise, but they can definitely irritate the knees.
5. A stand still throw, while not optimal for distance, is easier on the knees and usually increases accuracy. Us old guys sometimes beat the young bucks through accuracy.
Good luck.