How to help mentally ill husband gain back control

My husband suffers from multitude of different issues. He has major depressive disorder, ADHD and some symptoms of PTSD. He has been unemployed for over a year with no end in sight, he doesn’t sleep, he’s up all night playing computer games, if he does sleep its during the day basically unable to do anything else. When I tell him to do basic tasks throughout the day (while i’m gone at work) he tells me he doesn’t know if he’s gonna be able to do it because of his mental health. He refuses to take care of our 2 cats, like feed them, clean their litter box, play with them, even though we both agreed to getting them, he doesn’t cook because he doesn’t know how to and refuses to learn, he doesn’t really help me clean because he forgets when I ask, i usually have to repeat myself 4 times until he completes the task i asked for. He does receive money from the government which obv isn’t enough but he refuses to find a job other than the job of being a police officer which he got denied 2 times and stopped trying after. He asks me to pay for the majority of things since I have a job and do make a little more but the things is he seems to have no problem spending the little money he has on really really expensive things like his $4000 computer, $5000 worth of survival equipment just „in case“ we need it and more random stuff but then asking me if i can pay the rent in full, pay for groceries myself, pay for power and even pay his credit card due balance, it is driving me insane. I know you’re not supposed to call mentally ill people lazy because it creates a stigma that the mental illness is made up but I really don’t know how to tell my husband that regardless of his conditions this behavior is not ok. Anytime I bring up him getting a job or maybe helping me out more the only thing he says is „I’m sorry I can’t do anything about its my mental illness“. And he also recently decided to stop taking his medication for said illness. So what am i supposed to do here?! I really don’t be the asshole here and sound like im not understanding