When I felt I couldn't do it anymore; when ds2 was clearly not coping with school and things didn't seem to be improving, in fact they were getting worse..I took a step back, and tried a different approach.
I took him out of school and started home educating. Up until that point he had coped fine at school, and enjoyed it to some extent (ie proud of things he did there, enjoyed some activities, was part of the community in a positive way, not especially anxious or isolated) At home was a different story, he was quite difficult between ages of 8 and 11, but school seemed a haven for him and us. Btw, we never stressed about his writing or spelling, we accepted he was bad at these things, and it made his school life much less stressed, as we didn't fuss over homework, scribed for him etc.
However, in secondary it was clear the pressure was increasing, both academically and socially and so we had someone unhappy at school and at home. And nightmares with academic work.
At this point I stopped worrying about what other people thought, or what he SHOULD be doing compared to other people's children, and just deregistered him at the end of Year 7 (we tried Year 7 on Dh's insistence)
Then followed 2 years of what I can only describe as de-toxing. A lot of ds2's problems were much more apparent to us, when we were with him all day, but a lot of his problems slowly solved themselves because we had time and space to rebuild his confidence and approach his academic problems in a more leisured way. He now has friends and is like a different person, confident, polite, funny, independent. He is back a new school, with an EHCP for autism and dyslexia (and he definitely has a form of inattentive ADHD but school have said he shows no signs of it, now that he is confident and relaxed, he is one of better behaved pupils in classroom)
Sometimes when you stop trying so hard, and look at things in a different way, they can improve massively. Whereas if you keep flogging a dead horse (sorry bad analogy) it just doesn't deliver. In this case, trying in vain to fit ds to school and get him to fit the demands of an academic curriculum/social life/institution when he wasn't developmentally ready was setting us up for frustration and tension and anger.
I look back now on the tears I used to shed trying to do ds's homework with him in Year 7 (and ds2) and just wonder WHY WHY did I think I needed to live like that? Who was it for? For ds???really did he need a mother to feel so stressed all the time? Did he need to live like that?? No it was for school and institutional rules that someone in some bureaucracy ordained that we needed to do those things and live in that way.
Anyway, rant over, I have three kids in school, and my life is immeasurably better for taking a massive step back. People would say, oh how can you cope with him at home all day. Yes it was hard, but much harder was having an anxious despairing child and a stressed out mother.