Penny Parsons, 46, who brought a case of constructive dismissal against Josiah Mason college, Birmingham, finds out in August how much she will get for loss of earnings and injury to feelings.
She had resigned in September 2002 after being told she would have to teach AS-level religious studies despite turning her back on the subject 20 years earlier for ethical reasons.
However the college still made her teach the subject in her notice period and the stress of doing so led her to take sick leave in October 2002, an employment tribunal heard.
Previously she had taught caring and nursing studies at the college. "I had been very happy at the college and did not want to leave but this was an extremely stressful experience," she said.
Former colleague Jean Gillhespy said: "I started to have grave concerns for my friend and colleague who was driven to such a state of despair and exhaustion."
David Faulkner, representing the college, said it continually tried to help Mrs Parsons. He said: "We have heard at length the attempts the college went to help her through support."
Mrs Parsons, married with a 13-year-old son, told the committee the stress affected her home life and ruined a family holiday to Italy during the summer of 2002.
She said: "I was so absorbed with my problems with work that I was not able to talk about anything else."
The college disputed what she would be earning if she had not resigned.
Chris Grayson, principal of Josiah Mason college, said that Mrs Parsons'
claim that she would have progressed up the perfomance pay ladder was "fanciful to say the mildest."
Mr Faulkner also rejected the claim that, in her new position as an NHS health worker, Mrs Parsons would now have less holiday time and free time to spend with her family, adding that teachers often work long hours outside of the classroom.