Stubborn dad in denial, or just giving up?

So my daddy is a farmer. He only farmed trees for lumber in my lifetime, but he is a farmer.

Currently he can't get out of his house on his own. Forget getting in his truck (that he was very proud of and babied). It's impossible. His right leg is useless dead weight. He only walks by swinging it. He can't control it beyond that.

He has been brutal all summer about me getting this and that done in the farm, but now silence. His truck needs a tune up and I know because I needed it to haul hay and drove it in the last few weeks. My boyfriend, who worked at Toyota for too many years, offered to tune up my dad's truck. Dad chuckled and said "nah, I'll just drive it to my guy." I tried to ask how he planned on doing that. He said "well when I get better"

...you've been told by everybody that you're better than anyone expected after your last tumor resection. This is as good as it's gonna get and I don't think you'll ever drive again. I didn't say any of that part. I just said okay and went to my house across the driveway.

He has this nice 1955 Chevy Bel Air. Over the summer, it was top priority to get it washed and serviced. My son (8) washed it for him and begged Daddy to show him how to service it. Dad put a dust cover over it less than a day after it was washed. "The brakes are bad. It's not worth it."

Is he giving up? Or does he think some doctor's gonna have the magic cure to give him his life back?

Either way it's heartbreaking. Either way I cry at least once a day. Today he had an appointment and I thought he could get in the car without me while I moved the wheelchair. I came back when I noticed his door open. He was just sitting there, staring at his leg because it couldn't move to get in the car. Then after his appointment, I stopped at a gas station to give him a potty break. I stood outside the door and heard a crash. He tried to get up and fell and needed help up...I don't know how much longer I can watch cancer take more and more of my father.