An RAF pilot accused of trying to kill his girlfriend felt an "absolute monster" after he put his hands around her neck, a court heard.
Timothy Barry, 31, admits assaulting Sarah Seddon, 40, on 14 January 2018 but denies attempted murder.
Both were pilots based at RAF Benson in Oxfordshire at the time of the assault.
Flt Lt Barry told Oxford Crown Court he had tried to kill himself in its aftermath and thought he "didn't deserve to live".
He said: "I'd seen I'd hurt her and wanted the maximum punishment."
He said he filled a bath and cut both of his arms.
Flt Lt Barry, of Mill View, Cuxham, said the couple had a drunk a lot of alcohol before the assault to celebrate Sqn Ldr Seddon's return from deployment.
He said they consumed three bottles of champagne, a bottle of red wine, some beer and cocktails and were both "really drunk" at the time of the attack.
He told the jury they argued on a night out and when they got home.
But when asked how his hands ended up on her neck, he said: "I genuinely don't recall how they moved up."
Earlier this week the jury heard a medical assessment completed about five hours after the assault found Sqn Ldr Seddon "felt well and wanted to get up and go for a run".
During a 999 call following the assault, the trial has previously heard Flt Lt Barry said: "I have tried to kill my girlfriend by strangulation."
The trial continues.