Stalker ruined my life'.
Dr Jan Falkowski, 45, said he lost his friends, reputation and job because of Maria Marchese.
Argentina-born Marchese, 45, bombarded Dr Falkowski and his fiancee with threatening text messages as their 2003 wedding approached, the court heard.
One warned: "I kill the tart before I go myself."
Others professed undying love for him.
Marchese, of Bow, East London, denies harassment, threats to kill and perverting justice.
The hearing at Southwark crown court continues.