Teen anxiety and strange behavior

My daughter is 12 and had many problems at school, she is kind and sensitive, seems fell out from friends group time to time, there is a girl at school are very mean to her and she tried to ignore her but also cried a lot before go to bed. She sometimes tends to pick up wrong person to hang out. She try to stand up for herself and seek support from school counsel Recently she had glandular fever ( high fever) for about 5 days , after she was getting better , she start acting a bit strange , such us shaking head up and down for a few min when anxious or panic attacks ( it can be triggered so quickly whenever you try to talk about the symptoms, then she starts shaking uncontrollably- but hard to tell if it real ) , also she mentioned she is very hungry, but sometimes after she ate, she start retching ( uncontrollably, like she is not herself- in her word) it scares me and also made me very frustrated. She also have words phobic, when she heard “hot , meal, trousers “etc , chewing , she got very annoyed and ask us to correct it or burst to tears if we refuse to correct it . such as use “warm “ to replace hot. Anyone has been through similar experience? How should we be more supportive? Thanks！