Paedophile victims campaigner Shy Keenan was bombarded by 415 abusive tweets in five months.
Penelope Mellor, 53, of Coven, Wolverhampton, was sentenced for aggravated stalking at Chelmsford Crown Court on Thursday.
In a statement seen by the BBC, Ms Keenan, of Colchester, said it had also cost her tens of thousands of pounds.
Mellor was given a restraining order for five years, ordered to carry out 200 hours of community work and has to pay Â£2,000 in costs following her trial.
Ms Keenan, who founded the Phoenix Chief Advocates Consultancy, said many of the abusive tweets and emails took place when her son Ayden took his own life after being bullied at Philip Morant School in Colchester in 2013.
Ms Keenan's statement said: "It is impossible to exaggerate the real harm this woman and her associates have done by her relentless attacks on me, my family, friends and work associates, sponsors and supporters, to both my private and professional life and to my physical and emotional well-being.
"Most specifically during the loss of my child, who was bullied to death at school for being gay.
"I'm not the same person I used to be and now need expensive full-time care because of Penny Mellor's criminal actions."
Ms Keenan said she hoped the sentencing would put an end to Mellor's "reign of stalking terror".
She said her consultancy, which provided victim advocacy services, had been forced to close down and she had lost the ability to earn money as an advocate and a writer.
A victim of Twitter abuse has spoken of the "reign of stalking terror" that she was subjected to.