Hi Op,
Sorry to hear you’re having such a rough time, years 0-2 can be really hellish on the sleep front. Sometimes, little ones can just be really bad sleepers, mine was for the first 12 months, but I suppose one thing you can do is examine in a bit more detail.
So they are 12 months ish,
How many day time naps are they having ?
Do they go to nursery ?
Are they teething currently ?
Are they sick ?
what is their sleep environment like ?
when they go to bed, do they put up a fight or quite happy to settle ?
When they wake do they cry and scream loudly ? Or just more upset, want comfort etc ?
When you leave them during the night, what do they do ?
It sounds like from the info you have posted (of course could be wrong) that it may well have just become a habit the constant waking, if there is no pain from teething, no discomfort from illness, eating well in the day and optimum daytime sleep in the day/ enough wake time before bed, it’s habit driven …
Something I used was a method where you go in, give them a kiss on the head and say, I’ll be back in a minute to give you another kiss, then go back straight away and give them a kiss, then say the same, walk out the door, go back in, then do the same but extend the time between the kiss and going back in. I did it when I couldn’t get my little girl back to sleep and it seemed to confuse her, which made her quieter and more likely to relax between the wait time, it takes a lot of patience but in time, it worked.
I also think, if they arnt screaming and you have a monitor, just try and leave them a while, aslong as they are safe, it won’t hurt to see if they can get themselves back to sleep. I now say to my lo (but she is 2) okay I’ll be back soon to check on you, or I’ll say I’ll bring her milk or something, but I don’t go back and usually she’s so tired she just goes back to sleep between waiting