I hear you! My DD is the same.
Mine has ASD, as well as dyslexia some other stuff going on. She has reasonable adjustments and exam adjustments, but she just can’t do the exam.
She wants to go on to further study, the place she wants to go to require level 3 BTECH or 2 A levels with GCSE grade 4 maths or a Functional Skills level 2 pass.
She can do maths, but she doesn’t always recognise what she’s being asked to do, so, for example, she can do algebra, trigonometry, etc absolutely fine - she just doesn’t always recognise that that’s what she’s being asked to do. Plus she falls apart in the exam.
She wants to do functional skills level 2 as she finds it a bit more pragmatic than GCSE maths, but her college won’t let her do it as she’s achieved a grade 3 maths in the past. We are considering paying for her to do it privately through Learn Direct or something like that if it comes to it.
She’s doing a BTECH course - she passed level 2 with distinctions, but just can’t do the maths exams. Fortunately college have made an exception and let her do level 3 while retaking maths again otherwise she’d be stuck. She’s more than capable of doing the level 3 BTECH so it would have been a shame if she couldn’t do it because of maths.