This sounds like PDA - A pathological demand avoidance profile attached to autism. The NEED for CONTROL and AUTONOMY will dominate every single thing she does. I have a son with this diagnosis ( unfortunately I had to pay in the end for a wonderful assessor). That cost about £2000. The NHS blocked my request and I gave up. But now, having no money, I'd fight the GP in hindsight to get access to an assessment without paying all this. They are notorious for gaslighting mums, fobbing you off. The right to choose I understand is the pathway. This request should go in writing to the GP surgery. I believe the diagnosis is essential no matter what school or anyone will tell you. I am far down this road and you will be gaslit beyond your imagination. I have had challenges with the father/ ex also denying the reality that our child could be Autistic. You could end up dealing with that too. The diagnosis is very important.
The diagnosis imo in my child's case has helped secure the EHCP we now have pretty quickly in mainstream school. That should take some stress away. She'll be having an horrendous time trying to conform in school so will explode at home on you. School MUST accommodate her differences. They'll say you don't need a diagnosis bla bla. It's in best interests you do.
For now in the short term here's what usually helps -
I. Give her as much control as possible. Drop things like wearing pyjamas etc. What does she want to wear to bed. Well let her wear it and resist that feeling you must insist she wears what you decide.
Teeth brushing. Ask her 'you brushing tonight? Or is it a double Special brush tomorrow morning' you choose.
Shower/ bath - drop them every day. Negotiate with her, every other days fine. When it's all too much, let it go and give her wipes or something.
You have to drop all the things we think we need to make our kids do. They aren't that important but it's hard to do this. We fear it's going to corrupt children of we don't make them west their pyjamas etc etc but that's all bullshit.
Give her the TV and IPad when you need a break and accept the priority is YOU always.
Ask to meet with the school SENCO. You write to school and you say ' I believe with certainty my daughter is neuro divergent. Id like to meet to talk about a SEN plan in school which outlines all support / accommodations to reduce stress and demands on school. I would value the school supporting my request that my daughter is assessed for Autism and ADHD. ( The local authority usually commission an independent organisation to do these assessments). A GP cannot decide or tell you that your child is not ND btw.
Is there any person who can look after her and give you a break? Can you afford to pay someone? You need space and a break urgently because this situation is one of the most unimaginable difficult situations in parenting imo.
Your other option is calling social services and getting them involved to help you. To push through on an assessment, to support an EHCP.
Ask me any other questions if it helps.
The priority above everything here is YOU. Your well being and health. You have to get a bloody break. Is the ex able to give you a break. And I understand any fears that he won't be able to cope with her - but you must have a day off, a night off to cope with all this. ❤️