I've been thinking about your post more and more and might have a few things to offer.
It's hard to say right now because my boyfriend has been fairly well overall for a few months so I'm not in the pits of it right now. (But come December....maybe I can offer more).
I would not have made it this far in my relationship if I was still the woman I was when we first started dating. Some things that have shaped who I am today are the books I've read and the media I choose to consume.
It started with a subscription to LiveHappy magazine that came free with these skin care products I use. And I started reading the recommended personal development books. They've offered a different mindset to me.
Part of that mindset is being choosey about what I fill my time with. And over a few years I've made little changes that have helped me stay positive throughout the day.
In the car I listen to podcasts instead of gossip-ridden and fear-mongering radio shows. My favorite podcasts are Live Happy Now (go figure), 10% happier, one that my church does every week, and a few educational ones about topics I'm interested in (women's health, history).
On social media I consciously ignore political posts and links and use the "see less of this" options. I "unfollow" friends that post mostly negative things. And I have slowly but surely stopped hanging out with people that exhaust me, are negative, or are 1 sided relationships.
On the flip side, I've made a conscious effort to spend more time with positive people that are supportive and invest the same amount into our relationship as I do. The positive and supportive friends that I like and invest less into me as I do them, I've adjusted to match them. And when things are rough at home I schedule more outings with these people.
I limit myself to 1 hour/day of news consumption....which is just a news podcast that I like bc its not sensational reporting. Just as factual as I've found. Then I have an idea of what's going on in the world without being sucked into the anxiety of it all.
At home if I'm being ignored or things aren't good. I will put earphones in and listen to the music I like or one of my positive podcasts and then its easier to tell myself that he's not interacting with me because I can't hear him.
It doesn't sound like this is an option for your current situation but something that comes up every few months with my boyfriend is he gets so in his head he forgets about me and my needs and isn't great. He becomes accusatory about HIS needs not being met and I point out that I can't fulfill them because mine aren't being met. And I use specific examples of things he could do to meet my needs that would make me able to meet his. And then he has this flip of the switch because he realizes I'm right. But he couldn't see it before because he was too wrapped up in himself. But I haven't figured out how to bring up this conversation without a fight/irrationality on my own. I have to wait for him to call me out so I can call him out. If I see it happening I will consciously stop doing certain things for him so help the process along. (Like a back rub after a long a day....I'm under no obligation to do that...but boy does he realize when they stop coming and speed the process along)
Anyways. Maybe ill have more for you in December. Hopefully at least one thing here will resonate.
Sidenote:
@Mach123 I really appreciate your post. Thank you for sharing.