Overwhelmed overworked depressed partner

My partner and I have been together for a little over 4 years, during that time I've been struggling with chronic illness and he's been struggling with a horribly abusive job that he hates. We have had trouble with codependency with me needing to rely on him for financial support, transportation etc. But I have done my best to help with the cooking and cleaning etc. and maintaining a balance but at times there has been a lot on him.

Lately though I've been doing a really good job being independent, I have some income, it's not a lot but I am using almost all of it to help with the bills, groceries etc. I do pretty much 90% of the cooking and cleaning. I take my medications and keep up with my appointments. I'm doing the best I can to not be a burden on him. My insurance is in the process of being renewed and we have some concerns about some health symptoms I have but I'm doing my best to manage.

He has just been giving 110% and running on empty for so long that he's mentally unstable. Nothing I do seems like it's enough to help. He's stuck in his job and he's trying to fix it but in the meantime it is bleeding him dry. Not to mention everything in the world just being super hard right now as it is. He is just so unbelievably unhappy.

What should I do? Is there anything I can do to help him? I have my own struggles with my health but I am staying ontop of it and trying to help him here at home but I'm running out of ideas. I don't know what to do to make things better or how to help him.