Speaking as an attorney, find a local attorney and consult them. Promptly.
Virtually every area in the U.S. will have free or low-cost legal services available. If you’re not sure how to find them, contact your state bar association (city bar association if you live in a city that has one). They can direct you to appropriate legal resources.
That being said, in most (but not all) states, there is no requirement that you state a reason for divorcing your spouse. Most jurisdictions are “no-fault” which means that you can get a divorce because you don’t like your husband’s shoes - let alone because you urgently desire he get the best possible medical care. In a no-fault jurisdiction, you will need to fill out some paperwork (generally fairly easily obtainable through public resource sources) and then file the paperwork with the appropriate fee.
Generally speaking (again not in all circumstances), an uncontested, no-fault divorce is NOT going to involve spousal support. As a rule, if a divorce is uncontested by either party (which in practical terms means that nobody’s fighting about the terms of the divorce) and there are no children of the marriage (I didn’t note if you have kids or not, my apologies), then the courts will not involve themselves.
However, if you DO divorce your husband, be SURE - COMPLETELY SURE - to get as iron-clad a health care proxy as you possibly can in place IMMEDIATELY. Prepare it with the divorce papers and file it in the appropriate locations promptly. There are a number of places you can find templates online (or an attorney licensed in your state can direct you). Be sure to include not only who your husband wants making his decisions if he is unable to make them himself, but ALSO as comprehensive a list as possible of what he does and does not want. Have it notarized. Keep copies. Show copies to family members - be sure THEY have at least peeked at what he wants.
In my opinion, neglecting your husband is clearly not a viable option (neglect as in not providing him the best standard of care possible under the circumstances) - and either of the two remaining options involve some “burden to your neighbors”. You can rack up bills, and then go into bankruptcy at a later date - at which point, those bills go unpaid and prices get racheted up to cover the unpaid bills, or your husband can collect SSI or whatever public assistance is available to cover his bills and the taxpayer picks up the tab. In either case, this is not your concern. You don’t strike me as a habitual public assistance abuser.
Frankly, I can’t begrudge someone a share of my taxes when it’s far too easy for me to think “There but for the grace of God go I”.
Now ask me how I feel about public assistance abusers 