This has been happening for the past few weeks. If I sit on a chair for a few minutes, then attempt to move my right knee, or stand up, I will experience excruciating pain all along my joint. It's mostly under my kneecap. My left knee is perfectly fine. The thing is, though, that it isn't because of long periods of inactivity. If I wake up in the morning and sit on a chair for only a few minutes, the pain will be just as bad as it would be during the rest of the day. If I come back from a walk and sit down, it still only takes a few minutes before getting up will cause pain. When I'm sitting down, my knee will quickly start to feed stiff, and my first instinct is to move it. But when I do, it starts hurting.
I don't have health insurance so I don't know if I'll be going to the doctor for a while, so I'm trying to find answers online. Any help, like what could possibly be causing it or how to ease the pain, would be much appreciated. Thanks!