I'm so very sorry you're in such an awful situation! The only help I can offer is this:
indeed, write to your state and federal elected officials -- congressman, senator. You (or your husband) can find their names and addresses on line. Go to Google (or another search engine) and enter the name of your state, and the words senate and congress, like this: Wisconsin + senate and congress and links to their offices should appear.
No, they don't know you personally..but they ARE "your" elected officials, you are their constituents, and they do indeed intervene on behalf of their constituents...you. Often a letter from a congressman or senator will shake loose all sorts of things that an individual can't access on their own. Expect that one of their representatives will call you back, and want more information, perhaps even access to your medical records.
And of course appeal any denials from your insurance company. Each company has a specific procedure in place for doing that, and many of them have short times set up for you to do that, so check that right away (or have your husband check). Also be sure to tell your doctor that the company wants their money - doctors (and hospitals) will often reduce their charges if they know there are insurance problems.
Also contact your state insurance commission. You should be able to find this number in your telephone directory, under "State Government".
I'm so sorry you have to go through all this on top of your medical problems!
...I am not a doctor, nor health professional, and don't pretend to be one, here.....