If i am getting sharp pains in my knee, does that mean i am losing all of my knee cartilage?

No: Sharp pains can be caused by anything from a torn meniscal cartilage, patella chondromalacia, arthritis, or even referred pain from a hip or lower back problem. If you have knee pain interfering with activities of daily living you should have it evaluated by a trained professional to see what is going on.

No: There are many reasons for pain that don't necessarily involve cartilage.