Rant/vent: I feel like a maid or my dad’s mom.

My 80 y/o dad lives with me in my house, which is two floors and decent sized (I inherited it from my late mom), and while he is still sharp as a tack mentally he often acts worse than a stubborn toddler. He regularly hacks up a lung, can barely hear, and eats junk food despite three stints in his heart. He also refuses to do any physical work on account of a stupidity-inflicted injury. Why was it stupid, you may ask? Because he stubbornly refused to see a doctor after he tweaked his back while sleeping, only going to one after three months had passed and he could no longer walk properly. That was three years ago. He only has a PCP because I forced the issue; before that he hadn’t seen on in probably a decade.
He leaves dishes in the sink and trash in the living room. He won’t walk five feet to throw out a kurig pod and quite often just leaves trash on the counter above where the (easy to open) trashcan is. He gets crumbs all over his seat on the sofa to the point where I’ve had to dowse half the sofa in raid just to kill the bugs, and drops cigarette ash on my nice clean floors because he refuses to take the two steps necessary to get to our outdoor chairs. We moved here in 2021 and he has not unpacked a single box of his stuff, instead leaving boxes and junk strewn over all three upstairs rooms. I have not seen him do laundry in the three years we’ve been here, and I doubt he’s cleaned his bathroom at all. But when I offer to help even a little he refused to let me. If I ask him to help me do something simple—like calling the plumber because we have a leak and talking in the phone makes me hyperventilate—It takes him at least two weeks to get the thing done. But if I remind him he get snappish and accuses me of nagging. Except I ask him to do a couple of simple things (call to have the fireplace looked at, get his dirty pans and fork out of the sink, throw away his rotten lunch meat in the fridge) it sometimes takes months for him to try, and it’s usually half-assed meaning I have to redo part of it (and by half assed I mean like leaving food and grease on a pan he ‘cleaned’). That if I don’t cave and do it first to spare myself the stress. He would live in filth left to his own devices.
He uses his pain as an excuse to drag his feet or just outright not do something. And i get that he’s in pain; but so am I. I’m 35 and disabled. I have pain in nearly every joint (or more likely ligament and tendon) and muscle in my body. But the housework still needs doing. I get help from a home-care agency once a week, thank god, but that doesn’t help with picking up his mess the rest of the time. I’m not asking him to run the Boston Marathon; I just need him to care enough to make things a touch easier for me. I feel like a maid or a mother picking up after him. I've tried multiple times to tell him how I feel, how frustrated I am, or how much it bothers me that he would rather dump all the work on me rather than finding a way to compensate for his limitations, or how his laissez -faire attitude towards both my house and his health makes me furious, scared, and unheard. But he either dismisses my concerns or makes excuses/promises with the silent implication that I’m the problem.
I’m also his only person. My siblings aren’t close with us, he doesn’t have a partner or friends his own age. He refuses to make friends either. The only times he leaves home are for doctors appointments or if he’s going somewhere with me. Which means I basically never have my house to myself. It also means that the only thing he does all day is lay on the couch watch TV, from 10am to 11pm every day. The pressure of being someones only person is almost worse then the weaponized incompetence/helplessness.
Sorry for the long rant, I’m just frustrated and resentful.