Help with anti depressant medication for autistic teen

Hi

New on here but looking for advice my daughter has been school refusing for 5 years due to poor mental health (and other issues). We are at a specialist autism school but attendance is still very poor. In desperation I got a private diagnosis for depression which costs a lot to maintain (£180 every 6 weeks) and camhs is refusing to help us as they are saying we need to go back a step to CBT when we've tried that already. Does anyone know how we can get help and support?

Thanks