He climbed over a back fence to break into a neighbour's home and rob them, Matehe said.
She knew then that he was "beyond the help that I could give him".
It got so bad she stopped allowing him to babysit his younger sister, she said.
"When I really realised that he had gone too far was when one day I got a phone call at work [saying] he had left his 8-year-old sister at home by herself while he went out and got a hit."
Dylan managed briefly to give up the drugs but Matehe said it never stuck.
"I lost my temper and went knocking on the drug dealers' doors."
The message was clear: "don't sell to my son."
But nobody listened because they were off their faces on drugs, Matehe said.
The drug had such a hold on her son he told his mum that he did not care if it killed him, she said.
"When your child says: 'I don't care, you know', you have lost your child to that addiction.
"That family that has lost their child, I know how they feel.
"I know what they are going through."
People will judge them and try to say they were bad parents, she said.
"We are doing the best we can but our kids aren't listening."
Dylan Matehe died on March 7 this year and his mother said his death was initially completely unnoticed by those around him.
"They were so drug-infested they did not know my son was dead on the ground," she said.
"They were apparently laughing and joking..."
There were another two people upstairs who were in such a zombie-like state a parent was administering CPR, she said.
"The mother then came downstairs and realised my son was dead on her floor."
There were 10 people in the house, not one of them told Matehe what had happened, she said.
"For 23 years these kids were like family.
"People just don't understand it kills you ... people are out there saying who cares?
"We care, these are our babies."
The drug is dangerous, it needed to be taken off the streets, she said.
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