I feel your pain!
It was years ago now but our DS was a TERRIBLE sleeper from the word go - never slept longer than 45 mins at a time. Up screaming or playing or chatting, wide awake, after every sleep cycle, unable to get back down for hours. Wanted nothing to do with cuddles or stories. Fought sleep all the way, all the time.
No health issues or reflux or anything. Nobody believes us that it was as bad as it was. But I was honestly about to die of exhaustion and frustration. My immune system was in tatters - I had recurrent pneumonia for months because I just never slept at all.
We saw one sleep consultant who was fucking awful - told us our DS wasn’t sleeping because I had unresolved grief about a previous pregnancy loss (WTF?) and because he’d been born by c section. So that was useless and we only saw her once.
We saw another one who was brilliant, when DD was about 2 - she spent an hour asking us loads of questions about him and how we did things and what comforted him and what didn’t. Then she offered us suggestions that weren’t too far from what we were already doing, but which no other resource on the internet had come up with - and that really respected what we’d told her about our child and our parenting approach.
She didn’t subscribe to the usual stuff about having to remove all his comforts and ‘crutches’ so that he’d learn to re-settle, and so we let him have his dummies back without guilt, and that made a huge difference.
She also encouraged us to let him stop napping - in the face of huge resistance from nursery and everyone else in the world - and that helped a lot.
That said, he still didn’t end up actually properly sleeping through the night until he was four. 😩 And has never slept more than 8 hours at a stretch.
But at the time, when it felt like everyone was saying we were exaggerating how bad the sleep problems were (we really were not!) or we must be doing something wrong or be monumentally shit parents, or we just needed to man up and sleep train, it was a balm to my soul for someone to just listen and believe me and not tell me all the ways I’d made a rod for my back by not exclusively BF / BFing too long / using a dummy / etc etc.
She also said some kids just don’t need as much sleep. And some kids will really struggle to sleep alone until they’re much, much older than our culture accepts. And it’s absolutely OK to do things differently if it helps everyone get enough rest.
She was the second most helpful thing in the history of our child sleep struggles (after melatonin).
I’m not sure if she’s still working - I’ll try and dig her details out