I am so sorry you are having a rough time.
I am at the other end of parenting, with teenagers, and I just want to say that my worst sleeper has been my easiest teen, so there is payback!
I ebf all of mine, but they were so different
dc1 - slept from 11 pm to 6 am at 5 weeks. Then increased, so did 10 - 7 at 8 weeks. Basically 7-7 with a feed when I went to bed at 10ish. But really easy baby has not been the easiest of kids, very sensitive, very fiesty, you say white, he says black...
dc2 - hopeless sleeper for 6 months. Used to wake at 1 am and then every hour all through the night. I was on my knees. She did 7pm-1am but I could not shift that sleep slot to actual night time.
Then at 7 months I stopped offerring her the breast at night and offered her water. She slept through after 2 nights and became my easy kid
dc3 - by 8 weeks she mostly slept 10pm- 7am with one feed at 4 ish. At about 6 months she dropped the 4 am feed, so was doing 7-7 with a feed at 10 pm.
But she was the one who went through randoom phases of waking up in the middle of the night as a toddler. Just needed taking back to bed, but still. 2-3 times per week, awake in the night. And she has always been an early riser, she rarely made it to 7 am, always 6 am.
So swings and roundabouts. And I was tough. Once they were weaned and eating well, I only offered water in the middle of the night, it really helped then to stop waking.