Some problem in left knee. What it is?

When i was 28 i had got some knee pain. Not continuous only while climbing stairs. I cur not put my whole weight on it. If i do it used to pain so bad that i can fall. Several xrays and mri was done but No use. Then last year it became ok on its own. Now we had to shift house so i did all packing on my own. Too much stress apparently. Now i again have slight pain and when i straighten my knee i feel some flesh comes in between 2 things and then goes and very slight pain again on climbing stairs.i left dancing and exercises bcz of this and now my weight is also increased. Its 72. I dnt knw how it had become fine but i want to get rid of it naturally as i am ttc. Plz tell if its OA or meniscal tear or something else. I got ao many opinions earlier so m nt sure what it is