Rodger Morris, 65, who suffers from Parkinson's disease, mounted a two-month campaign against estranged wife Juthamas, harassing her workmates, loitering outside her workplace, and offering her colleagues cash for her contact details.
Morris's lawyer told Dundee Sheriff Court his medication for Parkinson's had "left him open to impulsive and compulsive behaviour".
However, Sheriff Alistair Hogg told Morris his behaviour was "completely unacceptable" and fined him £100.
Last year Morris claimed his wife had used special Thai spices to sedate him to put him off sex, and said she used him to gain UK citizenship – which she denies. He also claimed his £60,000 savings were spent on her before she left him.
The couple met via a website called Thai Love Links and married in Thailand in 2008, before moving to Blairgowrie, Perthshire, in 2009, then to Broughty Ferry, Dundee, in 2011.
Fiscal depute Ross Cargill told the court Mrs Morris left the accused in December 2011, but this year there were incidents at her workplace, Orchar Nursing Home, and reports of him hanging around the building.
Mr Cargill said: "On May 22, two colleagues of Mrs Morris were walking to their car after work and got into it. Mr Morris opened the car door and asked them for her contact details, but they drove off.
"Mr Morris then sent emails to Mrs Morris's colleagues offering money for her contact details.This caused her great alarm."
Morris, of Dundee, pled guilty to stalking his wife between April 1 and May 22 this year in Broughty Ferry, Dundee.
Kevin Hampton, defending, said: "He had spent quite a bit of money on this lady and due to ill health had lost his job and money became harder to come by.
"When she left he found it hard to deal with and he wanted to speak to her to sort things out.
"His medications for Parkinson's can have side-effects of impulsive and compulsive behaviour, and this may have played a part in his behaviour."
The sheriff said Morris put Mrs Morris in a "frightening situation", adding: "This type of behaviour is completely unacceptable."
Morris previously told how he was "heartbroken" after his wife left him.
But Mrs Morris categorically denied using spices to sedate her husband, and said he claimed to have lined up a Russian woman as a replacement.
Morris said: "I've learned my lesson and won't be doing internet dating again. You never know who you are chatting to. I feel like an idiot."
He added: "June always prepared dinner but she cooked my food first, served it to me, washed out the pot and cooked hers even though we were eating the same thing. Every night I felt very tired and lethargic. I think she did it so I'd be asleep by the time she came to bed."
However, Mrs Morris said: "I was happy at first but not for long. I went to work, came home and did nothing else.
"I gave him £100 every month from my salary – he needs my money because he is retired. I paid for everything."