All kinds of mental illness are often brutal on family members and can destroy relationships. Sometimes the reason is because it just go on and on for years and wears a person down until they can't handle the status quo. There may be a support group in your area. It would also be good in a different way to ask permission to attend a support group meeting for people with bipolar disorder (with or without your spouse).
Although there is mental illness in my family, I've only had to deal with it mildly, so I can only speak as one who has Bipolar Disorder (II). It took 10 years to get my medications adjusted to be as good as possible, and that's not uncommon. I was also in therapy for years, which was an essential element to getting better. I mention these only to suggest that you make sure (if possible) your husband is getting as much treatment as he needs.
The most important psycho-emotional need I have is to feel loved, which for me means (among other things) feeling accepted and affirmed. If you haven't already, it might be useful to dig into alternate ways to express your love (if they are genuine). I'm reminded of Gary Chapman's book,
The Five Love Languages (which I haven't read completely). There may be different things you can do that require less effort than you have been making, or perhaps things that are more effective. It's obviously going to make a big difference what your spouse's relationship with God is like (e.g., what kinds of efforts does he believe he is responsible for).
Other things I need like living in a clean house and eating well prepared meals, are less important. You may be able to form a prioritized list by talking with him about it on multiple occasions. Even giving him 100% of your attention while feeling accepting and staying calm may be profitable for both of you. I wouldn't really try to turn aside his ideas—that is, oppose them. Rather say something positive in return that doesn't challenge him (but doesn't necessarily agree with him). You can always tell him how you
feel about something he suggests, which won't challenge him like it does when you talk about him or how he is seeing things.
Some situations are too complicated to deal with in simple ways. In the end, he is responsible for what he chooses to say and do, not you. You may face a situation where you need to let him hurt himself to learn (but still be supportive however you can). Don't hide your emotions from him. If he says or does something hurtful, your reaction may carry much more weight than anything you might say. Our nature is to not do anything to hurt someone we care about, because then we hurt because they hurt. But trying to do this too much causes long-term pain as well as short-term pain. You'd need to use your judgment, of course.
But there is only so much you can do. As long-term caregivers learn, they have limitations. I visited an nursing home's Alzheimer's unit once. The nurses there were not permitted to be in that unit for more than a year. It was treated like a hard tour of duty. One reason is that wearing down is gradual, and a person can burn out without warning.
You need to treat your psycho-emotional needs as important along with trying to help and accept your spouse. One of the components of this is to maintain or build your relationship with Jesus, because he will definitely help you. I recommend talking with him in prayer, including (or especially) about the things that are bothering you, even if it is "complaining." I would especially seek God's help for strength and your ability to accept your spouse as he is, along with what God expects from you and doesn't expect from you. Note that life can be pretty awful at times, but God has given us this: we can be joyful because of him (and not necessarily anything else). It is a side effect of sanctification, which comes from abiding in Jesus and being obedient.
Make sure you are taking time away from caring (which includes withstanding his attitude, words, and behavior) for him. If he doesn't do it already—and you can do it if he refuses—is to not act on anything he wants to do unless it stays at the top of a priority list for at least a month. This is one way I learned to objectively evaluate what I felt I needed/wanted to say/do/buy.
I realize it is not within your control, but I will mention that if he wanted to, he could learn to intellectually evaluate things he wanted to say before saying them (or do before doing them). Some example questions he could ask himself are: Is following-up on this idea consistent with who I want to be? Are these words I'm about to say consistent with what God is like? (
But everyone who prophesies speaks to men for their strengthening, encouragement and comfort. [1 Corinthians 14:3, 1984 NIV]) How are people going to react to this?—perhaps I should wait until I think of a way to say this so it is pleasing to people.
You may be able to adopt an attitude that frees you from some pain by holding his words (or anything negative) in abeyance unless it persists for at least a month. Take the attitude, "sure, if things work out, but not this week." It goes along with the priority list idea.
Journaling the days that go well can help when you look back at them on bad days. (The same goes for answered prayers!)
