How to deal with teen with school attendance problems

Hi Nicholeen,
I don't know where to begin and where to end with this question but I'll do my best.
Our 14 yrs old daughter who is diagnosed with ODD and anxiety nearly a year ago begun having problems with her school attendance from the beginning of last academic year September 2023. We have had troubles in our relationship with her and to discipline her since she was 2 yrs old. We now see some of the ways we have gone wrong and wished we had heard of your book back then. Our daughter says she has experienced bullying, in particular regarding her physical appearance since school year 5 and 6 in particular (when she was about 9 and 10 yrs old). We cannot know for sure as this was at school and we were not there to witness and due to her very strong tendencies to be deceitful we can never know how much is true and how much is her over exaggerating things as she can have tendency to do to make herself a victim and blame others for all her problems which is what she does with us. Up until year 5/6 she used to come across like a very confident child, she used to love to dance and up until the pandemic she always enjoyed taking part in dance classes and shows. At around the time I mention above she started to get slowly but gradually more and more self conscious about the way others view and think about her. In the Summer of 2023 July/August she changed a lot, or seamed to, she began demonstrating behaviours we had not seem from her before as well as other familiar behaviours. These were staying in doors a lot, staying up till very late and staying in bed late, looking like she's day dreaming, deep in thought, staring for long period of times, locking herself in the bathroom/toilet for sometimes nearly 1 hour or more. She also complained that she was unhappy about her friendship group at school and wanted out(when she returned to school that September she would often avoid her friends by spending her lunch time in the toilets). She was fixated in having a glow up before returning to school, this led to her starting to wear make up, plucking her eyebrows, to name a few and spending so much time in the morning to get ready that she started missing the bus to school regularly, this started to bring her attendance down which is a big thing here in the UK, to the point where parents get fined and threatened to get taken to court. I made the decision to move her to a school which she can walk to in January but things have not improved much at all. We are at loss.