Unemployed and my medical debt was sent to collections, what can I do to keep this from getting worse?

I know that there are parts of this that I handled irresponsibly, so I'm just looking for advice on how to keep things from getting worse. In January 2025, I had a visit to the ER. Later received a bill for my $6650 deductible.

Since then, I've been hit financially over and over. I have been functionally unemployed since January 2025, paying for my rent and basic needs through freelance work and odd jobs. And then in May 2025, due to a family emergency, I had to move to a high COL area, resulting in me racking up another 6k in credit card debt over the course of the last year. I'm still looking for a steady job and slowly paying down my CC debt with my surplus each month. In short, I could not afford to pay this medical debt off then, and I can't afford to pay it off now. People around me kept telling me that medical bills will just "go away" and I shouldn't worry too much about it. But I just received a letter from USCB America, notifying me that they are trying to collect a debt that I owe to the hospital.

What recourse do I have? Is there any way to still work things out with the hospital? Is USCB legit? What do I do?