Brody, reading this from your perspective sounds in some ways like my interior dialogue over the past couple of years. My husband, for many complicated reasons, has had off and on insomnia and sleep troubles over the past 7 years, but especially for the past 2 years. I am a rather strict thinker on these matters, sometimes I almost echo my dad's constant maxim: "when the going gets tough, the tough get going". But that way of thinking, although it has helped me get through some rough times, isn't a great basis to build relationships.
A couple of things that I have learned from caring for my sweetie through his ups and downs:
-- caring for a sick spouse isn't as romantic as they make it seem on the movies. It is a drag. Don't expect yourself to think of it any other way--it isn't necessarily instinctive to sacrifice your time/goals/ideas to care for someone who is down, and sometimes you have to bite your tongue and help them the way THEY need to be helped, not the way that you think they need to be helped. We never fought ever until this health crisis happened...there are a lot of expectations and disappointments on both sides, but we have learned together that all of that just has to be put on hold until everything is a little better.
-- they probably blame themselves for how they feel. Just like you do, except they carry a double load of their self-blame plus your blaming them. Nobody could ever feel more depressed or guilty about their fucked-up health than they do, so they don't need you explaining to them all the ways they're doing it wrong. They don't need just one more explanation about just one more thing they could do to fix themselves.
-- statistically the single biggest positive factor in a recovery from illness or addiction is one close friend or family member (as a spouse you get to be both!) who loves and supports the person in recovery. I think that it has to do with the levels of frustration that they deal with, they just need someone who gives them the space and love to help take away that feeling of utter failure and despair. And that space can be the bit of relief they need that enables them to get out of their head and start looking towards changing the future.
All of that being said, these are the things that I've found that I can do that are really helpful to my husband during his difficult times:
--make healthy food accessible and positive, not another item on a list. Making roast beef with veggies or a batch of chicken soup doesn't involve that many minutes of work, but can make the next couple of days easier on you both.
--sharing time and good habits. Like others have mentioned, stretching together or rubbing/massaging her near bedtime can mean so much, and the physical and emotional benefits of loving touch are infinite.
--laugh together. Find a funny movie or even just read the jokes thread here on permies--laughing is truly good medicine and I have seen it help with everything from stomach problems to depression.
--IF she is up to it, get out and do something that you both like. Whatever your thing is, doesn't have to be healthy per se, just something that you both enjoy and will make her feel like a person instead of a problem.
Those are my thoughts! I wish all the best for you and your wife.