Caroline Crouch, 20, was smothered to death by Babis Anagnostopoulos who then staged an elaborate cover-up to make it appear as though she had died in a botched burglary.
In bid to make his lies look more believable he also drowned the family’s husky puppy.
After eight hours of police interrogation Anagnostopoulos confessed and said he lied because he did not want their 11-month-old daughter Lydia to grow up without parents.
Ms Crouch’s diary entries show how the couple had a fiery and toxic relationship, amna.gr reports.
In one she wrote: “I fought with Babi again. This time it was serious.
“I hit him, I cursed at him and he broke down the door.
“All I wanted was for him to ask how I am when I woke up. I woke up so weak and tired.
“I am thinking of leaving. I am thinking of going to my sister, I don’t know if I can keep going with Babi.
“I love him so much that I can’t leave him even though this relationship hurts me.”
When pregnant with Lydia in 2019, Caroline wrote: “Last night we fought with Babi because I had a meltdown because of my hormones.
“I yelled at him and hit him and told him I don’t want our baby...
“I am not well, I am very upset, I know he would never hurt my baby.
“My love for her is stronger than anything in the world.”
On July 3, 2020, when her baby daughter Lydia was a month old, Caroline wrote: “Today my little one is a month old- it’s also the day I told Babi I want to leave...I feel awful.”
Anagnostopoulos, a 33-year-old helicopter pilot and flight instructor, made a number of statements hours after the killing, telling reporters they had been tied up by robbers who broke into their home in Glyka Nera.
But police revealed on Thursday that this was, in fact, not true and Anagnostopoulos had confessed to killing his wife.
Watch: Husband in court in bulletproof vest as he is charged with murder
He admitted smothering her during a fight at their home in the early hours of May 11.
In the pilot’s grovelling admission, he said: “‘I tied myself up.
“I did everything because when I realised I killed her, I thought of my child,” the Daily Mail reported.
The confession came as pictures of Anagnostopoulos hugging Ms Crouch’s distraught mother at her memorial service on Wednesday were released.
The embrace took place as detectives arrived to call him away from the service - claiming they had arrested a new suspect and needed his help to identify him.
However the suspect was in fact Anagnostopoulos himself.
Police were able to unravel his lies after data collected from a fitness tracker on Ms Crouch’s wrist showed her heart had stopped beating before the alleged break-in took place.
Tracking data from Anagnostopoulos’ home also showed him moving from the attic to the basement of the house and back again, despite claiming to have spent all night tied to the bed.
Data from a security camera at the home also showed its memory card had been removed at 1.20am - again, hours before the alleged break-in took place.
A senior investigator, working on the case, said it did not take Anagnostopoulos long to confess.
“He said he had been fighting with Caroline for some time and they were fighting that night, exchanging heated text messages while he was on the ground floor and she was in the attic,” they said.
The investigator said that when Caroline texted her husband that he was “stupid,” he lost his “cool”.
“He disabled the home’s surveillance camera, discarding its memory card, before charging up to the attic where he had another heated argument with Caroline, pushing her onto a bed there, and smothering her to death,” the police officer added.