Solidarity from me too.
My son is 4 months old and was a brilliant sleeper after having a very difficult start initially. For the last few nights, he's spent far more time awake or unsettled than asleep.
I have a 3 year old daughter who has spent over a week in hospital. My partner hasn't left her side once. I've visited every day except yesterday and spent most of the day at the hospital with no opportunity or place to sleep.
In the evening, I bring our baby home (he is EBF), play with him, change, feed and settle him to sleep. He spends all night every night sleeping in 20-30 minute blocks before waking up again.
I am BEYOND exhausted. I don't know if this is the dreaded so-called 4 month sleep regression or a change in his routine being away from his dad and sister, constantly travelling to and from the hospital. But, it's SHIT, and I'm on my own with no option yo hand him over to somebody else whilst I sleep.
Before my daughter was hospitalised, my partner would take over for a couple of hours in the evening, then I would feed in the night and get up with our baby between 5 and 6am, every morning. So, a bit of help but still not enough.
Hang in there mummy! Insist that your partner helps look after the baby, even alternate nights or 2-3 nights a week. Offer to get up with your pre-schoolers if they wake in the night (and just secretly hope they don't!).