Wel come to HCM,
It seems that you might be having slack muscles of knee joint and might be having some problem of ligament or cartilage
Go for x-ray knee and find out the cause and consult orthopedic surgeon.
Go for Quadricep
exercise 10 minutes in the morning and evening.
Avoid sitting on legs and squatting position.
Do not sit with cross legs.
Ok and bye.