Yes, I completely understand what you are going through.
I just euthanized my beloved hen "Filamena", last Monday. I was deeply grieved to have to do make that decision.
She was a very special hen from the first time I saw her, very talkative, pulled on my pants and sat on my feet. I raised her from the age of four weeks old. However, a year ago she became ill with a reproductive disorder. She was saved from death three times over the year. My vet treated her and was able to help her recover twice. Then, four months ago I had to do CPR on her, as she was choking, and started to turn blue. That hen was surely blessed, she was almost three years old. She lived a happy life here with me, as I am sure your hen lives with you.
Last Monday, after being ill for three weeks, my hen suddenly stopped eating, couldn't walk, had labored breathing and was flailing her wings for balance. When I saw this, I new her last day had come. It broke my heart to make that decision, but, I was also glad to have her for that year. She was always happy, and lived a quality life, foraging and living with her flock mates. I provided her with many accommodations to help her: steps and ramps around the yard, a safety net in the coop, many special meals, spa treatments for her condition, and trips to the vet. So yes, I completely understand what you are going through.
But, the fact that you are seeking opinions on this decision, tells me you are not ready to throw in the towel. It's hard to euthanize an animal that is eating, drinking and seemingly healthy. When they stop eating, drinking, having labored breathing, cannot walk, then it is easier to make that call. You don't want them to suffer. But, if there is no hope for a good life with a measure of quality, having to force feed, keeping them in captivity away from their flock mates indefinitely. Then, that too is a form of suffering.
So, discuss this important decision with your vet and husband. Then, when you are confident in your decision, you will be grieved when she is gone, but firm that you did the right thing.
They're not just livestock, they are part of our pet family, just as important as the dog or cat.
God Bless and peace to you.