Paul Mason told Ms Kinsella he had bought her a wedding dress, as well as showering her with gifts.
The 40-year-old left rambling messages on her answer machine and repeatedly sent her text messages referring to her as "pumpkin".
The messages included: "Your wedding dress is ready pumpkin" and "Pumpkin, I will be coming down Saturday to see you and the kids" - in reference to the True Stars Academy, her performing arts school for children in Hoxton, east London.
He followed her to public events and even visited the grave of her dead teenage brother Ben, who was stabbed to death aged 16.
Mason, from Hatfield in Hertfordshire, once turned up at an event with perfume, oils, a scarf and numerous CDs containing his own recordings.
On another occasion at the Lion Centre, next to Millwall Football Club, he managed to get close enough to hug Ms Kinsella.
The actress, who gave evidence from behind a screen, told Bromley Magistrates court: "I had been given a warning from the Home Office about him which really frightened me.
"The whole thing was just really worrying. Without having been told by the police to be vigilant I might not have been so worried about it." S
"I remember noticing him at the Lion Centre in the crowd. Then all of a sudden he came up to me and hugged me.
"I didn't know what to do. There was a lot of press and people around so I just kept it short and sweet and said 'Hi Paul' and left it at that."
On another occasion, he arrived at the Bromley Theatre when Miss Kinsella was taking part in a dress rehearsal.
Mason had arrived and one of the theatre staff had told her "friend" was waiting for her.
She continued: "When I saw the message 'you will be my wife' it really shocked me. It was frightening.
"I felt really very threatened by his messages and the whole thing was escalating before me. That was what worried me the most."
In another incident, he turned up at the Ben Kinsella Trust with two bags of presents.
When he was told that Ms Kinsella was not there, he "became aggressive" and lifted his shirt to reveal a stab wound.
In a victim impact statement, the 31-year-old actress said: "It has impacted me in terms of worrying me because it has been going on for so long.
"I never know when he is going to turn up. I work with young people...I have to be extremely cautious.
"I don't know what he's capable of. I feel anxious about giving evidence."
As Mason was jailed for 26 weeks, he declared: "I don't give a s***".
He was also handed an indefinite restraining order banning him for contacting Ms Kinsella.
Sentencing Mason, lead magistrate Alan Dee said: "In the process of the trial, the victim needed to relive the offences and give evidence.
'You have a track record of previously harassing individuals.
"You have been calculated in your conduct.
"We need to take into account the prolonged nature of the offences and the impact on Miss Kinsella - she couldn't know when you would turn up.
"Your previous record in this area is not good. There are four previous harassment convictions since 2008 and so the period of custody will be one of 26 weeks."
Mason shouted: "You're going to take into consideration that I was stabbed and my mum died from being stabbed? I'm appealing the conviction and the sentence."
Mason, who refused to co-operate in the preparation of a pre-sentence psychiatric report, was banned from going to Finsbury Library, entering the N1 area of London, attending any location where Ms Kinsella is present and contacting her directly or indirectly.
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