Giving evidence at Winchester Crown Court yesterday, Nicola Brown said she had not told medics she shook 19-day-old Jake Long.
The baby died on December 19, 2014, after being born at home in Agincourt Road, Buckland, on December 1.
Speaking for the first time in court, the 42-year-old said Jake had not taken feeds on the day of his death and she intended to call a doctor if he did not take three feeds.
At around 10am she tried to feed him for about four minutes but looked down and saw he was not breathing.
Brown wept in the dock as she told jurors: ‘I think I panicked and shook him when he wasn’t breathing.
‘I’m so scared I’m going to lose my baby boy.’
Asked by her barrister Patrick Gibbs QC why she did not tell medics at Queen Alexandra Hospital that Jake had fed badly on December 18 and not at all on December 19, she said: ‘It was only through thinking back on things that you remember at the time.
‘I was an emotional wreck. I can’t even remember trying for an hour to feed him in the night. I was that distressed.’
Brown told how she was on the phone to her now-husband Jason Brown, 44, as she tried to feed Jake.
‘He made a funny noise, then I looked at his eyes, and he stopped breathing,’ she told the jury.
‘I was on the phone to Jason. I said “I’ve got to go and phone an ambulance, Jake’s not breathing”.’
Jurors heard that Nicola Brown made various searches online about baby epilepsy and babies’ eyes focusing in the days preceding his death.
Brown said she thought she was being ‘paranoid’.
But asked by Mr Gibbs if she had any regrets she said: ‘Yes I do. I regret not getting him help. If I had, my son might still be in my arms today, with me. That’s all I want. I want to know what happened to my son.’
Brown denies murder and two counts of causing grievous bodily harm with intent.
The court previously heard Jake suffered 17 rib fractures.
Mr Gibbs asked: ‘How did he come by the injuries that killed him?’
Nicola Brown replied: ‘I don’t know, I wish I did.’
Jason Brown, of Seymour Close, denies causing or allowing the death of the child.