You need to have a chat with him about what he is able to do.
It's not fair for you to do it all but it's also not fair to him if he isn't able to do it without pushing himself into a more serious condition.
You both need to come up with a solution that works, whether that's oven meals, batch cooking, hiring in help, getting additional childcare and find a way to make this an equal responsibility to contribute to.
I am a disabled parent. I can give 50% in a relationship but that might not mean I do 50% of cooking or washing up as I physically can not do that, but I would find a way to take other things off a partners plate in order to make the balance of responsibilities more equal.
In that respect he also needs to find a way to contribute financially whether that is on benefits or whether he has a plan for finding work that is within his realm of capability be that part time, work from home, self employed, a side hustle, whatever. His 25k will take some load off but it won't last forever if he uses it to buy aids or support - which I'd urge him to do as an investment to his health and responsibilities.
FWIW when DS was about 4 weeks old he developed meningitis and the same day I developed sepsis. We were both admitted to ICUs in different hospitals and our families both thought we would die as that was where we were both headed. It was a scary time. DS fully recovered but I developed CFS. It's not how I imagined being a parent at all and recovery has been so slow. There were days where all I could do was change nappies and lay and feed the baby. He's almost 6 now and I am still cripplingly exhausted after doing the school run twice a day and it's only 100 steps away from my front door. It's hard for my family to see how hard this is on me because they see me sitting or laying down and it looks like I'm not doing very much, but at the same time I'm also finding ways to try and build my strength back up and plan my days to the T so that I am sharing some responsibility.
Everyone recovers differently. YANBU for expecting a contribution and an effort towards wellness, and expecting him to not grow complacent with you doing everything but you need an honest discussion about what he is capable of and what steps he is taking to make sure he can work up to an equal partnership.