I know there’s a regression around this age, but we’re on our knees. He’s never been a good sleeper, but I used to cosleep and breastfeed through the night, which kept us all sane. Unfortunately when he got to seven months, he became such a terrible biter that I’ve now given up BF entirely. In the last month or so he’s also started crawling and rolling round the bed, which is as dangerous as it is infuriating.
A couple of weeks ago we started putting him in his cot, in a room he shares with his three year old sister. He’ll now go down quickly for naps with a bit of rocking and a bottle, and will go down for the initial bedtime settling within five or ten minutes.
However, after that it goes tits up. He wakes pretty much every 30-60 minutes (every sleep cycle?) and wants more rocking or more bottle, or sometimes just screams for ages and doesn’t know what he wants. I suspect he needs to learn to go to sleep without the rocking and milk, but I don’t know how to teach him without waking his sister up, and we don’t have the option of separate bedrooms. We get to a point every night where we give up and he comes into our bed, where he thrashes around and is generally a menace.
Naps are 1 hour from 9am ish, and about 1.5 hours from 1/1.30 ish so I don’t think he’s overtired at bedtime.
Is there something obvious I’m missing or do we just have to wait it out? How could we deal with the self settling issue? His sister was an awful sleeper until her first birthday but I BF her and coslept longer and just rode it out that way. He’s not safe to have in the bed but the current situation with the cot is unbearable 
Thanks in advance.