I often think that I would prefer to euthanize my dog myself. He is absolutely terrified of going to the vet (of strangers as well), and having to do it there makes it that much worse. I'm one of only a handful of people he trusts.
That was why we used an at home euthanasia service for our dog. He hated going to the vet and had to go multiple times a week toward the end. We didn't want to have him scared and stressed in his last moments.
Look into at home options if the time comes. We actually found that the cost was not much more than doing it at our vet's office. I think it was $500 at home vs $400 in office. $100 extra to give him the best end possible was the least I could do.
Same, he was mostly bed bound as he had been for months, the vet came to our place. My wife and I were crying like no other, was this the right time, the question was haunting us, still does. He still appeared to like to eat, but he was paralyzed, needed help to poo and pee, even to stand to eat, but he could still sit on lap and seem happy but even that was mitigated by the fact he was on a lot of gabapentin. The moment of euthanasia came and he was asleep throughout the whole thing. Broke our hearts but gave him a painless exit. I will say this though, kids under 10 need not be there. I love and miss you everyday W.