Ryan Storer left abusive voicemails and also visited the woman’s mother’s home, on February 10, said prosecutor Anna Pierrepont.
“The complainant is very frightened of Mr Storer and asks for a five year restraining order,” she said.
“She says “Since the end of the relationship he has become worse, and I am becoming afraid of what he might do next.””
Ms Pierrepont said that the relationship had a number of “jealousy issues” and on one occasion Storer threatened to commit suicide while he was driving on the motorway.
Matthew Taylor, mitigating, said Storer “fully admits that he became too committed” to the six-month relationship, which ended in October, last year.
Probation officer Raqia Bano said: “He admits that he was besotted and still claims to be in love with her. He failed to comply with a harassment warning.”
Storer, 24, of Thrumpton Lane, admitted stalking when he appeared at Mansfield Magistrates Court, on Wednesday.
He was given an 18 month community, with 30 sessions of the building better relationships course.
He was ordered to pay £100 compensation and £85 costs.
A two-year restraining order, banning him from contacting his ex-partner or going to her road, was also imposed.