To be honest. Many who file bankruptcy are honest people who never either didn't accept responsibility for paying debt, or like you, who, with medical, had no choice and even on SSI, will probably barely make enough to survive. Chapter 7 IS for people in your situation. You haven't got it and even if you do get SSI, you will probably not be able to afford the expenses. Coming up with the money to file when you're broke is a problem.

People in your position shouldn't feel shame about it. You didn't choose to need medical care. There's no shame in it when you are honest and really want to make an effort. There is no sense of pride when doing it, and it can be stressful, but it will get the collector's off your back. Then if you do have money in the future you can still choose to pay them.