What happens to an elder if POA quits and there are no other family members or friends to take over?

I am at the end of my rope with my Uncle. Got POA's and Will done in June. Since early July, he was hospitalized 3 times and sent to rehab for 4 weeks. He came home mid-August and fell 3 days later, hospitalized 1 wk, refused rehab and consented to going home with home health care (I live very close by). I visit almost every day, anywhere from a half-hour to a full 8-10 hour day depending on what needs to be done. He still manages independently in his apt., but skills are slipping. He is 92, apparently not in dementia, legally blind, and uses a cane (consistently now since his fall). The 2 significant changes I see since he came home are difficulties with bowels, and getting to the bathroom on time, resulting in soiled clothes and soiled toilet and floor. The other change is how he uses the cane - he takes baby steps and doesn't (never did) point the cane to find direction and reference points, no matter how much coaching I try to give him. The cane is basically for balance the way he uses it. The extremely slow gait could be part of the reason he doesn't always get to the bathroom on time. I set up 3 weeks of PT, OT, and an aide as soon as he was released. He bitched and complained about every one of them and wanted to quit. I told him the DEAL was, either rehab or home health care. He chose the HHC, so he had to stick it out. Now they are all done with him, and all of the opinion that he is doing as well as can be expected, but should not be living alone and ought to be in a NH. Up to this point, he had been completely self-sufficient with dressing, toileting, washing himself (sponge bathing only), food prep and eating, and housecleaning surprisingly well. That is why I advocated for him every time a doctor or other HC professional said he needed a NH. What has declined since August is the toileting issues and cleaning himself properly, and also the much slower walking. I have coached him to wipe down the toilet twice every time he has a BM, but I cannot expect him to get down and clean the floor. So I am there anyway almost every day, and end up scrubbing the bathroom, and cleaning the floors wherever he has tracked the poop (so far not excessive). I wear gloves for all cleaning and handling the laundry, using appropriate disinfectants like bleach or PineSol. I have been doing a lot more cooking for him since Doc said low fat/low chol/low salt diet. Gone are the days of cold cuts and frozen dinners. I told him no more boiling water at the electric stove, & no more getting on hands and knees to clean up kitchen or bathroom floor. He wants to resume doing his laundry in the building, but it is impractical for him to even try, so I have been going to the laundromat for him - pick-up, wash-dry-fold, iron, pack up & deliver-put away. I do a lot more housecleaning as well, since I told him he is not to attempt using mop & pail anymore. Like all other caregivers, I do everything that he cannot do outside the home as well.
He also refuses to allow a mobility instructor to come in and teach him how to use the proper kind of cane. He also has refused hearing aids when he was just diagonosed with hearing loss in both ears. He hears the lower pitches better, so I have to try and speak in a lower register with more volume, and after the third attempt repeating myself, he accuses me of shouting. By the end of the day, my throat is very sore and hoarse. So I have to physically suffer because of his stubborness.
The money issues have become unbearable. He gave me DPOA and now regrets it, accusing me of taking away full control from him. I have arranged Direct Deposit of his SS & Ret checks, and plan to set up automatic bill-pay as well, leaving any remainder in the bank for future in-home health care expenses (I am also thinking of the Medicaid application process in the future). He is having extreme anxiety over not feeling the cash in his hands. This is the sticking point for him - like a fixation. He always cashed his checks and we made money orders to pay the bills, and he kept the remainder. This was a very inconvenient and cumbersome procedure every month. He is used to getting the remainder and keeping it in his wallet, which is excessive and unsafe, especially if I have to start hiring people to come in and help out when I cannot be there. I am quite agreeable to giving him $100 at a time when he runs out of money for incidental expenses, but he is not satisfied with that. Everything hinges on the money for him. He behaves spitefully and refuses to cooperate with me unless I agree to give him extra money. Now he wants to talk to the lawyer and so do I. I am concerned that he will destroy everything I have tried to set up in order to make both our lives a lot easier. In essence, if he refuses the asssistance that will prolong his IL status, he will quickly lose his functionality & end up in NH or on home hospice 24/7 if he qualifies. If I quit, what happens to him?