Sudden changes to chronic knee pain

Patient: I have had knee pain for the past 15 years or so (I’m 21, female). I told my doctor and he finally, last year, gave me referral to xray and bloodwork. He was suspecting lupus or rheumatoid arthritis, but both tests came back negative. The xray also didn’t show anything. He said to wait a few years and then come back again.Recently (8 months ago), I moved to Europe and my knee suddenly got worse. It is crunching very loudly and gets sore after it. Sometimes I wake up with it really sore and it carries through the day.A week or so ago, it started to hurt more. When I was younger, the pain was at the front of the knee (seemed to be between the knee cap and the shin bone (tibia?)), but now it is on the outer side. There is a small bruise on that side as well. It constantly feels like my knee is being pulled to the outside.Today I was on my knees while cleaning the carpet and afterwards when I got up my knee hurt a ton more. It also felt really weak, like it was about to give out. This lasted for 20 or so minutes and then it went away (I was standing during this time). My boyfriend compared my knees (by moving the cap around) and said they felt different, although I can’t notice.Any thoughts on what this could be? I don’t know if the chronic pain is linked to it in any way, or if it is just completely unrelated. I do not remember bumping into anything with it. I kind of remember just waking up one morning and realizing it was a lot more sore than usual.