Kuntal Patel, 37, is accused of trying to kill her magistrate mother my putting abrin in her Diet Coke drink.
Prosecutors say she was angry that her mother "forbade" her from marrying her boyfriend Niraj Kikad.
But in police interviews she insisted she bought abrin from America on the "dark web" because she was suicidal.
Ms Patel, from Plaistow in east London, arranged for the drug, which was hidden in a candle, to be delivered to a friend's house last December, Southwark Crown Court heard.
But when she picked it up, she said she became "scared", smashed the glass-enclosed candle and decided not to kill herself.
Jurors were told that in a police interview, she said: "I never wanted to hurt my mum. I have hurt her enough.
"There is no way I wanted to live without my mother. I don't have much family, and she is my family.
"Because I was torn in both directions I thought I would take my own life."
Ms Patel said she threw away the poison after she became scared.
Earlier this week, jurors were told that her mother Meena, who sits on the bench at Thames Magistrates' Court, was "manipulative" and tried to break her relationship up.
She also beat her daughter, locked her in their home, and confiscated her passport and credit cards, the court heard. But Ms Patel said she would never harm her mother.
She told officers that if she wanted to kill her mother, "I could have pushed her down the stairs, I could have given her an overdose of her blood pressure tablets", but she had not, the court heard.
She also told police officers that she looked up buying ricin after watching an episode of Breaking Bad.
Asked what effect the poison had in the episode, Ms Patel said: "Just a painless death - that was in the programme."
She denies trying to murder her mother and acquiring a biological agent or toxin but has pleaded guilty to two counts of attempting to acquire a biological agent or toxin last December.
The trial continues.
A graphic designer has said she bought a poison to kill herself rather than her mother in a Breaking Bad-inspired murder plot, a court heard.