Lucy Meadows became pretty good at avoiding the press. She slipped out of her back door before the paparazzi arrived and crept round to school long before lessons started, staying in the classroom way after hometime.

But it was difficult, the primary school teacher told a friend via email in January, knowing there was a price on her head. "I know the press offered parents money if they could get a picture of me," she wrote on New Year's Day, just before she contacted the Press Complaints Commission (PCC), asking for journalists and photographers to stop hanging around outside her school and home in Accrington, Lancashire.

All she ever wanted, she told her friend in emails shared with the Guardian, "was to be me", the person she always felt she was meant to be, a woman and not the man she had been born 32 years earlier.

That's why, just before Christmas, pupils at St Mary Magdalen's C of E school were told by the head that when they returned after the holidays, the teacher they had known as Nathan Upton would henceforth be known as Miss Meadows.

"Mr Upton has recently made a significant change in his life and will be transitioning to live as a woman," wrote the head, Karen Hardman, in a letter that made headlines in the national press.

On Wednesday pupils were told that Meadows was dead. Results of a post-mortem have not been released, but Lancashire police said on Friday that there were "no suspicious circumstances" surrounding her death. It is believed she killed herself.

Why she took her own life is not clear, although it will be the subject of an inquest in due course.

But Helen Belcher, director of TransMedia Watch, which monitors media coverage of trans issues, said Meadows suffered "a huge amount of monstering and harassment by the press when she was very vulnerable around Christmas. That level of press attention could not have helped her mental state one bit."

In the New Year's Day email to a friend, seen by the Guardian, Meadows complained that the media had published one of her wedding photos, and had lifted other pictures from her siblings' Facebook pages. She also discussed her decision to come out.

"I was lucky to have a supportive head," she wrote, "but I think I'd have done it here regardless as I couldn't put it off any longer and I have family and financial commitments as well. The guidance I've had from the trans community has been generally sound and very much appreciated, and I'd like to be able to say I've given something back. I suppose the best way for me to do this would be to educate the people around me and children at school – I am a teacher after all!"

She described the lengths she had taken to avoid being photographed. "I became pretty good at avoiding the press before Christmas. I live about a three-minute walk from school so they were parked outside my house as well as school. I'm just glad they didn't realise I also have a back door. I was usually in school before the press arrived and stayed until late so I could avoid them going home."

She said "many parents have been quite annoyed with the press, too, especially those that were trying to give positive comments but were turned away".

Meadows' gender reassignment became the subject of huge media interest in December after Hardman's letter to parents was leaked to the press. The story was covered by various outlets, but it was Richard Littlejohn's column in the Daily Mail that prompted Belcher to complain to the PCC.

In a piece headlined "He's not only in the wrong body … he's in the wrong job", the polemicist asked whether anyone had thought of "the devastating effect" on the pupils of Meadows' change in gender. As the PCC's rules dictate, the commission was able to act only when Meadows herself complained on 4 January, when a PCC complaints officer sent an email to all UK media passing on her concerns.

On Friday, more than 3,000 people signed a petition urging the Mail to fire Littlejohn and demanding a formal apology for the stress and pain, the petitioners said had been caused to Meadows by the columnist, the paper and its readership. A vigil has also been organised outside the Daily Mail offices in Kensington, west London, on Monday at 6.30pm.

On Friday Kate Green, the Labour MP for Urmston and Stretford and shadow minister for women and equalities, said: "It is totally unacceptable to humiliate people or invade someone's privacy when there is absolutely no public interest in the story. Surely the media have learned from Leveson to stop this kind of horrendous intrusion into individual's private lives."

The Daily Mail defended Littlejohn's column. A spokesman said: "It is regrettable that this tragic death should now be the subject of an orchestrated Twitterstorm, fanned by individuals – including former Labour spin doctor Alastair Campbell – with agendas to pursue."

Campbell had tweeted: "I hope journalists are doorstepping Dacre, Murdoch and Littlejohn for their reaction to Lucy Meadows' suicide. The Mail really is scum."

The spokesman then quoted Guardian media commentator Roy Greenslade, who stressed in a Guardian blog "that there is no clear link – indeed any link – between what Littlejohn wrote and the death of Lucy Meadows."

If you or someone you know is affected by these issues and need to talk to someone urgently, the Samaritans is available 24 hours a day on 08457 90 90 90; or email jo@samaritans.org or visit the Samaritans' website