A friend is a consultant in the NHS. She has given up work, after initially trying part time, because her disabled child's needs are incompatible with a career. I know several women in the same boat. I can count six just off the top of my head, right now.
You could literally not do what many parents do, with high needs disability, and work, in a paid sense, too. Sleeplessness is part of it, as is the child's frequent inability to attend school at all, as are endless appointments (physio, OT, SLT, EP, audiology, ophthalmology, orthopaedics, play therapy, art therapy, paediatrics, GP, ATS, DCYPS, school... because co-morbidities are very common with SEN, and so needs in one area may mean needs in others are found) and there are an increasing number of kids out of school altogether, because the country is many thousands of specialist school places short, and mainstream schools have raised the drawbridge and systematically say they can't meet needs.
It's also just a different parenting experience. As my consultant friend told me, "I spent 15 years in clinics telling parents all they needed was to be a good enough parent... but with autism, that's bullshit! You lose your temper, or forget to plan and scaffold, or to have a Plan B, and the week is a write-off!"
It is not the same. Everything is much harder work. Everything takes longer, including the time a child will take to recover emotionally, if a parent who hasn't slept in weeks loses their temper and raises their voice. That doesn't mean it isn't at times fun and rewarding and that there aren't highs - my kids are, also, brilliant and hilarious and endearing and fascinating. It's just different, and in some ways a lot more demanding.
Routines are not flexible in our house. We have to allow an additional 20 minutes to leave the house to allow for them. If my husband expected me to cater to man-baby tendencies on top I think I would fucking lose the will to live. As it is, he's an ally and support, which is what keeps the show on the road. I am never so grateful for having married my college boyfriend, and former friend, and for having kids only after years together first, as when things go wrong in this house I am not alone in dealing with them, even if that means a hug and a cuppa when he gets in from work and learns what's happened that day, on the bad days - and his delight when the kids have something brilliant to be proud of on the good ones, too.
I don't actually spend much time with parents whose kids don't have SEN any more, because the lack of comprehension is too exhausting. But I do in fact work - as a volunteer SEN supporter, as I have a couple of law degrees and know the system very well... and it is infinitely flexible, so I can fit it around the kids.
I doubt many here would regard that as valid, though. I mean, it's unpaid. I could earn doing it; there are plenty of advocates who do. But I regard that as exploitative, given what most parents really need from me is to feel less alone, and like someone understands and cares, and if they pay anyone, it should be the experts and lawyers they need, in a system that deliberately avoids complying with the law (as nothing is cheaper for a Local Authority than giving a disabled child nothing at all - and if you think that's cynical, then lucky, lucky you in your ignorant bliss).
Ignore those who sneer at what you do, OP, just because they don't comprehend a world beyond their own noses, so assume your own life in some way resembles their own, and that your mental and physical load is the same as the one that can be neatly dovetailed around a working life in paid employment. They have no clue what our lives are. But your peers - your real peers, the many women, and some men, walking in your shoes - do. They get it.
I see you, OP. And I am so sorry you don't have the support from your children's father that you deserve to have.