A posthumous note written by Dame Esther Rantzen said she was "deprived of any choice over my own death".
The farewell message was released as the 86-year-old broadcaster and campaigner's family confirmed she had been laid to rest in an "incredibly beautiful" private funeral last week.
The Childline founder, who was diagnosed with stage four lung cancer in 2023, died at her Bramshaw home in the New Forest, Hampshire, on 30 September.
A larger memorial service is expected to take place at a later date.
Rantzen's daughter Rebecca Wilcox said the family had been inundated with messages since her death.
"It's been hugely comforting to know that people around the world felt the same way about her as we did," she said.
Dame Esther became a prominent campaigner for assisted dying in her later years, something MPs voted against legalising in September.
In her note, she wrote: "It would have transformed the way I died if the law had allowed me to ask for assistance to die when my life had become unbearable.
"I was extremely lucky because I had the talent, skill and support of my local Oakhaven Hospice.
"But I was still deprived of any choice over my own death by the current messy criminal law."
She said she had become "too physically frail to take the flight" to an assisted dying clinic in Switzerland.
Addressing those who opposed the change in the law, she wrote: "Rest assured I will not come back to haunt you, I have better things to do."
She also wrote: "Nobody wants to shorten life, just to shorten death."
Arthur Stickland, who has been on the committee at Bramshaw Cricket Club for 60 years, said the That's Life! team played annual matches against the village side for about seven or eight years.
He said Dame Esther always came along with the show's presenters and backroom staff, and remembered her as "an ordinary person".
"You wouldn't know she was actually here. She just mingled amongst the crowd," he said.
He said she was a vice president of the club, and that in the village "everybody knew who she was and nobody tried to bother her".
Dame Esther presented That's Life! for 21 years and set up Childline in 1986, and later The Silver Line helpline for older people.
Her family has asked for donations in lieu of flowers to Oakhaven Hospice, Childline, The Silver Line and Cats Protection.