Hon, here is some tough love. God will take care of you. I promise. When He closes a door He opens a window. Go ahead and have the faith. Put in the 2 weeks notice.
You are in a catch 22 situation. You need the job for insurance, but need the insurance for the job that is making you sick. There are some low cost clinics, and I bet they can/will help.
I would leave. IMO, you are doing good by giving them the 2 weeks notice. From the situation that you wrote, I would be gone. You are a better person than I by staying. YOU DO NOT OWE THEM ANYTHING. Some nurses choose to stay because they feel like they own the company, pts, co-workers, ect something. You do not. Good luck, and please keep us posted.
Oh, yeah, I would also be making some phone calls to allow authorities know what is going on.