Denver Beddows admitted battering his 88-year-old wife Olive with a pan and a hammer at their home in Warrington.
He said it was an act of mercy because his wife was "terrified" of ending up in a home or a hospital.
Beddows, who earlier admitted attempted murder, was given a two year suspended sentence at Liverpool Crown Court.
After his arrest, he told police he had failed his wife because he had not managed to kill her.
He said: "I have made a mess of it and now she is still suffering... Why didn't she die?
"She is the most beautiful woman in the world and I have made it worse. I would happily be a murderer."
The court heard he fractured her skull at their home in Dam Lane in Woolston, on 4 February, by striking her on the head with a pan before then bludgeoning her with a lump hammer.
The couple had been married for 65 years and were devoted to each other, the court heard.
Psychiatric reports showed Beddows - a man with a history of depression dating back to 1962 - was "clearly under a great degree of mental strain and was not thinking straight", his defence team said.
Mrs Beddows' physical and mental state had also been deteriorating and was being treated for anxiety and depression.
Deputy chief crown prosecutor Geoffrey Fryar, said Beddows had "resolutely refused the help of social services" and the couple's son and his wife helped out by visiting up to four times a week.
Beddows said his wife repeatedly asked him to kill her because she told him she would rather die than go into care.
Mrs Beddows is now making a "good recovery" in hospital, had forgiven her husband and wished to be reunited with him, the court was told.
Judge Clement Goldstone said that was "indeed true love" and described it as "an exceptional case".
"Although this was a terrible crime, the blame which attaches to you for what you did is far outreached by the tragedy of the situation," he said.
He said they were "acts of last resort".
In a statement, the couple's family said: "The last 12 months have been particularly difficult, as we all attempted to cope with mum's mental illness, which is still yet to be diagnosed.
"At present we are supporting both mum and dad, and ask for some privacy whilst we come to terms with the situation."
A 95-year-old man who tried to kill his wife has been spared jail because the judge said it was "an exceptional case".