jlm,
I'm so sorry that transplant is not an option for Bryant. This disease is a bi***. And the pain is just not fair.
I know that this sounds harsh, but you need to make sure that you, or someone, have medical power of attorney, so that decisions can be made. We went through the DNR questions and contacted hospice and had the family fly in. It was very, very difficult. So, I do know some of what you must be feeling.
Hospice will keep him comfortable, if that's the choice that the two of you make. They will work with the doctors and get him anything he needs, up to and including pain meds.
You can also get respite care, so that you can take a nap or a walk or whatever for your own health and sanity.
God bless and let us know what we can do to support you here.