I wish you & yours as much comfort as possible right now, that really sucks am very sorry man

((Re your last visit there though...that is NOTHING to beat yourself up over, it'd be nice if we all had sweet flowery goodbyes everytime we departed from someone we loved but life just isn't like that....for your case, so many -- have seen it myself and it looks absurdly painful -- so many have either neutral or negative experiences and it haunts them, *you* were doing what a good son-turned-man would do and your Dad was w/o a doubt proud-of & thankful-for you, you being there to physically help is what convinces him you care he knows you love him

[[and on the "I coulda/shoulda"...he was being stubborn as you said, I suspect I would be the same way in his shoes TBH, whatever his reasons he did not wanna go and, w/ diagnosis being unexpected,
that is bad luck that is not *anybody's* failure. Cancer is so *s-wordty and savage, blew my mind when I found that the overall "human cancer% rate per-capita" was, in a lifetime, 38.4% for men&women....over 1-in-3....and just comes outta nowhere so often, am seeing it with my beloved cousin who I can't get to (geography) went to hospital for head-pain some months ago and turns out it's a tumor, she's 39 or 40 and has a 1yr old girl[the odds of them getting it under control are near-zero, it quickly went to amygdala & eye-socket so they're cutting what they can but already stopped her from proper mobility and cognition is expected to go very quickly]]
Wish there was anything anyone could do besides good-vibes man, sorry for your situation :/ And the covid thing...same with my cousin, her husband helps her into the facility-entry and has to stay behind / let them take her inside to her doctor, realllly sucks..
Given your situation & thread-title, have to imagine the resident echo dealer would offer you an extension if anything went wrong on your gear (ie their usual 7-day-window), unsure how 'big' $1k of gear is to you but would be nice to hear an echo rep confirm it.
Best of luck, am so happy you didn't have a negative last-encounter I have a friend who is still utterly haunted by his, you did precisely what you should have it would not have been right to force him (I guess some may not agree on that, I know I wouldn't want to be forced & would do whatever I could to avoid it and that would have me "against" those who were trying to force me...you couldn't win" from the position you were in, but you did 'play your cards' as perfectly as you or anybody could have, having one's son coming to help is a hell of a good memory & knowledge you'd raised your child right, you've truly got zero you should be regretful for Re your last encounter, there was NO expectation of that prognosis when you went to the house, your actions - and his awareness of them - were exactly as they should've been given the situation hell he'd probably have been OK going in the car w/o resistance if he'd had an inkling of the prognosis himself, it's bad luck we just like to forget[or didn't know] how common it is I mean if 9 people read this reply, 3 or 4 of the 9 either have-had or will-have cancer.....it's truly a shame that we don't have more-advanced testing, seems the routine/default diagnosis for cancer in the US is found when the physical tumor's pressure inside the body hurts and not 'symptoms of cancer pathology', still can't wrap my mind around how there isn't some middle-ground test whether urine/blood/etc that'd be done annually along w/ routine bloodwork..)