I passed an informal support plan three years ago. My head suddenly called me into her office and told me she was removing my year 13 group six months ago. She had previously shouted at me in front of students twice. I had a mediation meeting where she lied and denied everything. She also told me she wanted me to do another support plan. Her excuse was that my exam groups have been failing for years. My performance management was signed off for those years. What on earth should I do? Am so tired.and extremely anxious. Have been signed off for the last four months.