Jessica Bussert, 41, said yesterday that she came close to jumping in front of a train after she found herself doing administrative tasks for colleagues.
The data analyst is now claiming damages of £500,000 from Hitachi Data Systems for discrimination in an employment tribunal that could prove a test case for transsexuals.
The executive, who, as Joshua, had been used to working on multi-million pound contracts with huge IT clients, including the US Department of Defense, claims that she was made to book hotel rooms and arrange meals after she returned from surgery as a woman.
"I jokingly said that when I had my breasts done the company must have assumed that they used my frontal lobe as a filler. I seriously thought of suicide. I considered filling the flat with carbon monoxide.
"I stood on the platform at Ealing Broadway watching the express trains go by. It was so much more than the career: it was people trying to devalue you as a human being. It's like acid poured into your soul," she said.
Ms Bussert says she was shocked by the "transphobic and bigoted" reaction she encountered after changing sex. She claims her business trips abroad stopped and she found herself working for colleagues who had been promoted while she was away having facial feminisation and breast surgery.
Her wife Sharon, 40, to whom she has been married for 15 years, says she was terrified her partner would commit suicide during the ordeal. "She was quite serious about her situation," she said. "I am saying this as the person she lives with. I saw it."
Ms Bussert said: "I was having panic attacks and even suicidal thoughts. The way these people reacted to me has been so horrible and cruel and heartless. I felt a lot of despair.
"My family and my friends love me and I have really been accepted by these people but ultimately you need a job. I have worked in the IT industry for 25 years. I am proud of the work that I do."
The IT consultant was originally recruited by Hitachi in the United States, where she had owned and run her own successful IT company in Indiana. She has three grown-up children from a previous relationship and two adopted children of Haitian background whom she raised with Sharon.
She was diagnosed with gender dysphoria - a condition suffered by a person being born into the wrong gender - after counselling at the Kinsey Institute in Indiana in 2003.
Ms Bussert now lives full time as a woman, but has yet to have the final stage of gender reassignment surgery.
She decided to transfer to London for Hitachi whom she had been working since 2001, hoping it would be a more tolerant environment than the Mid-West of America. But the dream soon went horribly wrong. The £88,000 a year job proved a "nightmare" when she went to work as a woman after the first stage of surgery.
"I left in March last year to go for my surgery and I returned in early April. When I went into the office in my appropriate gender role It was the fist time I had interacted in the workplace as Jessica.
"I presented myself as a professional businesswoman. I showed up to a meeting with my peer and during that meeting I was told my peer was no longer my peer but my boss. They had promoted other people in the team," she said.
"Before, I was in charge of all the consulting in the Middle East and America, but now it was my new boss who was doing this. Now it was my job to arrange the travel, hotels and meals for my new superiors. I was doing really menial tasks."
Although still technically employed by Hitachi, she is now looking for a new job. She is seeking £500,000 in damages at an employment tribunal to be held in the next few months in the UK. She is making £1.93m claim against the company in a parallel case in the United States.
Transsexual support groups said last night that it was not unusual for transsexuals to face discrimination after they had changed sex.
Christine Burns, of Press for Change, said: "Our research has shown that as many as 30 per cent of transsexual people suffer discrimination and harassment in their place of work . As many as 50 per cent of transsexual people feel obliged to move to another job and the majority thereafter work one or two levels below their competence."
Hitachi refused to comment on the detail of the case, but disputed Ms Bussert's claims.
The company said: "This matter is currently subject to employment tribunal proceedings and it would be inappropriate for Hitachi Data Systems to comment. However, Hitachi Data Systems strongly refutes the allegations made by Ms Bussert in their entirety, and will vigorously defend against her claims."
Box Name: The facts of life for transsexuals
Transsexuals have won the right to change birth certificates to their adopted sex, and marry.
It is illegal for an employer to discriminate against a trans-gendered person unless the person's sex is an occupational qualification.
There are up to 400 sex change operations carried out in Britain every year.
The number of transsexuals in the UK was recently estimated to be above 4,000, including 300 who are married.
Male-to-female gender reassignment is three times more prevalent than female-to-male gender reassignment.Reuse content