Sorry for reposting but I am in desperate need of help and need advice. PLEASE HELP ME!

Sounds similar to medial collateral ligament sprain. I beat it after 5/6 months while continuing to run. But you have to do quad and ham stretching/strengthening exercises that your physiotherapist will recommend if it's MCL.

I've had both an medial collateral ligament sprain (left knee) and pes anserinus tendinitis/bursitis (right knee). They feel -- are -- very different. Spraini was the result of a specific trauma. In my case, collision in soccer. Sprains are not overuse injuries. With a sprain there is point tenderness and achiness, but not the recurring sharp or stabbing pain of bursitis. With a sprain, there is more likely to be discoloration and swelling and a general feeling of achiness and instability. In my non-professional opinion, an mcl sprain would be an extremely remote possibility for a running injury. Still it is possible that you could have twisted your knee badly enough to injure yourself if you were runnng on a bumpy trail or something. But you would have known you did something bad the instant you did it. (My mcl sprain trauma was the most painful thing I've ever felt in my life, including childbirth without pain meds.)
Pes anserinus bursitis and pes anserinus tendinitis are typical chronic overuse injuries... both are much more likely candidates for what is ailing you. ... just my opinion.

Hi there,

I am not a doctor but I am a triathlete who experienced a similar issue last year. After increasing my mileage a bit too quickly, I had pain on the inside of my knee. It would start off as a dull ache and then finally be so sharp that it would force me to stop running.

I was diagnosed with plica band syndrome. There is a "spandex" like band that wraps around the inside of your knee. It is normally pliable but when overused (due to a weak medialis in the quad) it become taught when the knee doesn't track right. The thigh bone then "catches" on it causing the sharp pain. This may NOT be what's happening to you but it's a possibility. Regardless, I would get thyself to a sports doctor ASAP.

Recovery for me consisted of a cortinsone shot (liquid magic) then PT for several weeks. No running...lots of strength training the inner quad and lots and lots of stretching particular the hip flexors and hamstrings. As for biking...flats are fine but no hills. I upped my volume in swimming, started water running and using the elliptical to maintain cardio fitness.

Hope this helps...but do check in with a doc!

Good Luck!