Lack of routine and structure

To start off with I would like to apologise for this post since it's going to be bit of a rant and it's about my daughter, Chloe's school. 

Background info: she is in an autism specialist school, accommodating 20 students, all staffed 1:1 or 2:1. Chloe has been 1:1 since the start of the Summer Term. 

The main problem comes down to staff illnesses which leads to staff shortages, which means her timetabled staff are changed. This term has been hideous for her but she has coped exceptionally well. 

She has now completed all her exams, meaning she does not need to do her maths and English lessons any more. Half of her timetable is maths and English and she is more anxious than ever. These lessons are now unstructured, she has nothing to do, and her staff always changes to what she is expecting. This is causing her a lot of distress and yesterday, it was only 30mins before she left to school to come home. 

Our issue is that she does not understand why she can't have the staff who are on her timetable for her lessons. She is leaving school in a few weeks so her anxiety is through the roof and having little routine and structure is not helping at all. She is now extremely demanding and controlling at home (this is due to anxiety and so she is in control of what is happening). She gets angry when the slightest thing is changed or if she needs to wait. If anyone knows how to deal with these school issues, lack of routine and structure, please let me know!! 

I just can't deal with this school anymore but Chloe has been through hell with school life, and she does not give up and she is a fighter. This is probably the 3rd time she has come home early in 3 years nearly. No matter how hard it gets she always wants to give it a go and make the best out of everything. 

On a positive note: when she came home (we call this a win and a good choice) she watched TV and ate snacks. In the afternoon, she picked her sister up from school after her exams, and took them both bowling, McDonald's and saw their father. They had great fun yesterday. 

Many thanks,

Lucy