Hyperextended Knee Symptoms

Last night I lay on my bed watching TV and I stretch really hard and I felt instant pain in my left knee. I looked up things possible and it could be "hyper extended" sounded feasible, but symptoms were more extreme than mine. That's what he says about this "You will experience several symptoms at once if you hyperextended knee. You can hear or feel a pop, and it might feel as if your knee has been thrown out of the line. You will discover the pain in his back and sides of your knee, and swelling in the early hours of the injury. The main thing you will experience is the inability to continue to play, run, etc. on your knees. It will become unstable. You might be able to walk on it, but it will be painful. "
Now, I do not feel pain in the back or sides of the knee it feels like its right in the middle of the bone and it hurts, but not extreme pain, as they describe. I have to limp around my house hunting a year because i cannot straighten my knee all good lol. Reflections on the pain?

could be a tendon or ligament has been stretched, the ice help with the pain and make it heal faster, only a doctor can know with certainty