Daniel Anderson was jailed for three years by a judge who described how he had turned the woman's life into a "living hell".
Leeds Crown Court heard Anderson would constantly turn up at the victim's home and subject her to vile abuse as he demanded cash.
She was forced to hand over sums of up to £250 at a time during the offending which took place between February and August this year.
The victim eventually reported the abuse to the police when she had just £1.38p left in her bank account.
Lucy Brown, prosecuting, said the woman resorted to living with one of her other sons and giving her bank card to her ex-husband in a bid to escape Anderson's abuse.
The court heard the 30-year-old would turn up at her home Leeds in the middle of the night and would time his visits to coincide with the times she received benefit payments.
Anderson also subjected his mum to a torrent of distressing phone calls and voice messages.
On another occasion he smashed a door at her home.
Ms Brown said the offending began in February this year.
It continued during the lockdown period as his mental health deteriorated and his addiction to cocaine and spice grew worse.
Anderson initially turned up to her home asking for sums of between £10 and £20,
The demands increased until she was being forced to hand over an average of £100 on a daily basis.
The court heard she began to sell personal items as she ran out of savings.
In a victim statement to the court, the distraught mum described how she had suffered a breakdown over the offending but still loves her son despite what he put her through.
She stated: "Due to the crimes by my son I have been unable to sleep. I am anxious and scared.
"I love my son and have always tried to do the best for him.
"I might not have always made the best decisions but I have always had the best intentions.
"I have given every penny to my son, leaving myself and my other children short.
"My relationship with my other children has been massively strained. It is difficult for them to understand what he has done.
"I want to repair the relationship with my son. I love my son with all my heart and I hope this will turn his life around."
Anderson, of Stratford Street, Beeston, pleaded guilty to one count of causing fear of violence by harassment and one count of criminal damage.
He also pleaded guilty to making threats with an offensive weapon in relation to a separate incident when he threatened his neighbour with a crowbar.
Anderson has previous convictions for assaulting his mum and burgling her home.
He has also served a prison sentence for causing serious injury by dangerous driving.
Nick Worsley, mitigating, said Anderson is embarrassed and ashamed of his behaviour.
He said: "At 30 years of age he has an unenviable record and this is a vicious cycle.
"He takes spice and cocaine and it causes him to behave in the way he does.
"When he is off drugs he is responsible and does everything he can to be a responsible member of the community.
"He accepts that he has said unforgivable things to her and he has behaved in a way that is unforgivable."
Sentencing, Judge Tom Bayliss QC said: "You have made her life a living hell.
"She has become fearful of living in her own home.
"She states what no doubt every mother feels for her son.
"She loves you and has tried to do her best for you and you have repaid the love she has given you by making her anxious and scared.
"She has given every penny she has to you."