My rabbits are sick, not eating, and hunched. What can I do?

I am sorry your rabbits are sick and passing away. I would try and locate an exotics vet somewhere around you. Even if you have to drive a little further. Unfortunately the picture and posture does not tell why they are sick. I get concerned about something contagious if you have had other rabbits die. I know it sounds sad but if a rabbit dies I would recommend taking it to the state lab for a necropsy (autopsy in people). This way they can take tissue samples and send it to the lab for hopefully a diagnosis. However we would prefer to keep the rabbits alive. Parasites like coccidia can cause death, infection, viruses, dental disease, toxins and maybe food source. The rabbits really need to have a fecal, blood work and maybe x-rays. You can try to force feed them at home with a product like critical care but they need to continue to eat or there intestines stop working which can cause fatality.