Stubborn father, live-in son, and cheap father.

My father, he's 83 and a widower of two years. He does not drive anymore (forced by the family and the DMV), has diabetes, heart issues, sight problems, hearing problems, forgetfulness, and he has mild dimentia.
As a good son, I moved in with him, to help, with the support of my siblings and his brother. But our help falls on deaf ears.
He is stubborn, but also a freindly guy.
He wants to do what he wants to do. He wants to make decisions on his own, and those decisions are very often "bad choices", despite logical solutions. He thinks he can still drive a car, even though he has totalled 3 cars in one year. We finally got him tested twice by independent driving evaluators....they said "no way should he be driving".......and now he is not driving.
He's has a lot of money in the bank, but he loves the dollar store.......so much so that he will not buy things from regular stores which means he buys sub-standard products that in the long-run, wastes money, or could harm his health.
He waits until he has one pill left, for his heart medication, before scrambling to get more.
He wants to be in control of his meds.
I suggest to him...."if there is an emergency (eatrhquake, or.....), you should always have two weeks of medication. He dissagrees because he will be spending more $$ that way (shoot me now). Thank g-d I have a 15 gallon barrel of water in the house for the two of us. He thinks that is unessesary.
Since he does not drive or have a car anymore.... he wants to take the public bus, because it's the cheapest. I told him, that the money he's saving on a car and insurance, could go to UBER or a taxi for independance. He does not want to pay for either. He can barely walk 1/4 mile before needing to stop for rest......yet there he is, wanting to take the public bus.
In essence, he is a cheapskate. He can afford better and safer transportation for the rest of his life.....but he wants the cheapest transportation, despite his walking disability.
When I take him to the market, he says, "I can walk a lot if I have a market cart." I told him to get knee braces, or a high-end walker. I bought him a top-of-the-line walker, but it sits there in the livingroom, unused. He walks at 0.1 miles an hour, like an injured penguin.
I understand he wants his freedom, and his respect. I understand he does not want to be seen, or want to think he is incapable of walking on his own without a walker.........but the reality is, he could be a lot more mobile with the walker.
If it sounds like that I won't take him everywhere he wants to go.....that's correct. I won't take him to get 99cent values at the dollar store. I refuse to. I tell him that the crap food he buys at the dollar store is......utter crap. I tell him that 99cent apples and lettuce and other food is "on their last legs of freshness"....but he refuses to believe otherwise, even though it rots in 2 days when he buys it. Basically, he is willing to eat rotting food.....but I am not....and I won't let him (or me) eat rotting (or close to rotting) food.
He spends hours on the net, researching and spending $$ on miracle supplement cures for his aging....healthy joint cure products, brain power supplements, diabetes miracle cures, vitamin supplements,.....yet he will not engage in a proper fresh plant diet. Yet this is where I have already stepped-in, and I cook him fresh and custom healthy meals almost every day, out of my own pocket.
I just don't know how to handle this stubborn man. He says he loves my help, but if my help means that I succomb to his unhealthy and irresponsible living.......frankly, I feel like an enabler.