Right sounds more like variation of patella tendonitis (jumpers knee) it comes from over tight quads. It may have even have started to involve the pre patella bursa.
Do you stretch the quads? If so how exactly.
Either way ice the knee, foam roll the upper quads to loosen pressure on tendon. Dont stretch quads directly. You could even get a marathon stick to help with self massage.
If after two weeks it still feel unstable it probably is.

Best thing to do next: Get some imaging on it and buy a strap if is shows ligament or meniscus tears. Get a good practitioner who can refer quickly if this is the case.

just to help: what is the most aggravating movement for the knee and which point on knee map hurts the most when it's in this position?