I have knee twist and instability 4yr ba

Confused with rheumatoid and orthopaedic issue... I have taken 3 MRI, no ligament tear, increased cartilage signal seen in lateral facet of patella, grade 2 chrondamalacia patella, mild ACL edema, very minimal knee joint effusion extending into suprapatellar bursa and recess My problem is Getting knee weakness and knee joint locks or stiffness in lef knee lateral side and swelling in knee joint, Doctor says IT band strain and tendinitis of knee joint, I can feel if not doing physiotherapy getting swelling and IT band, i may think any arthritis or over used knee joint injury, But I have done all RA rheumatoid test, came negative but rheumatologist says serronegative ra, orthopaedic says normal and nothing.. Am confused about what to do..