What should we do? This is bad

Close family member diagnosed with cancer one month ago, underwent chem and radiation. Turns out he never had cancer, he had a stroke what the dr's called a tumor was swelling on his brain. As a result of chemo and radiation and a weakened immune system from that he became dehydrated hospitalized and developed pneumonia and a secondary fungal infection in his lungs which eventually led to intubation where we stand now. The (new) Dr now says he will not survive off of intubation and we plan to stop that in just a few days.

It is certainly possible you have a case based on what you say here; you should take a brief description of these events as well as your medical records to a malpractice attorney and see if the attorney thinks you have a claim; often you need to contact several attorneys to find one to take the case; the review of your case and records is often free and then they will normally take the case on a contingency fee basis if they think you can win; you would pay only if they collect for you.