Something is attacking my joints (and I have no insurance)

I am in between jobs and have no health insurance at the moment. In the past few weeks, something has started happening that is completely new to me. It’s kind of scary for me.

2 weeks ago, my husband and I went on a trail walk (ended up doing 3 miles round trip). I wouldn’t go on a walk if I wasn’t feeling well. I took my dog, and at about the 2nd mile she bumped me hard (excited about a squirrel perhaps, I forget now) and my right knee buckled a bit. I was able to get back to our starting point ok. I don’t recall having issues the next day.

A few days later, my right knee started buckling with just walking my dog to go to the bathroom outside. I think the knee felt slightly stiff. It got better after a day or so.

Over the past week, both knees have felt painfully stiff, but there’s no hot spots, no visible swelling. Just stiffness and pain (especially on stairs). I also get a painful pressure spot in my right hip but it doesn’t feel uncomfortable to move. No other symptoms. No clicking, heat, swelling, etc.

I have no idea what is going on and why the sudden issues and the way it fluctuates between left knee/right knee or both knees. I did call the doctor that I pay out-of-pocket. I asked for a steroid but don’t really know if I should take it or if it will help. I don’t take steroids often because I know it can damage the bones - I know I need labs and probably and X-ray or CT scan but I just can’t deal with a large medical bill right now 😔