Super slinger I don't have any advice as I only have a 14 week old but we might be in a similar position...we've kept him with us but I'm thinking he needs to be in bed of an evening, not in my arms. Could you try a transitional phase of being in a basket or on the sofa beside you sleeping then graduating to her cot?
My favourite book about sleep issues is 'teach your child to sleep' by the millponds clinic but although it has got some good suggestion about reducing night feeds and gradually teaching them to self settle I have not read anything about a DC crying so much when they are being held. Have you tried other ways to comfort her like rocking her, walking with her etc to try and break the pattern before gradually reducing the support you give her?
I think the four month sleep regression has just collided with separation anxiety... The last two nights I've put her down, fed her as usual and instead of falling to sleep she's fed then rolled away and cried. Then proceeded to cry until she's sick. She's saying 'mama' as she cries if that helps give you knowledgeable lot any clues as to what the problem is (it's not that she wants her mama as she's six months old, and as much as we all think our children are genius...)
So that's two nights running, crying until she's sick. She's still in my arms so it's not that she's scared/ has been left or something, though on the first night I tried putting her down in her cot etc to see if anything would calm her, but it didn't...
THEN once I finally get her off (after two hours!) she's waking once, sometimes twice an hour to feed - last night I fed her TWELVE TIMES between 9.30 and 7.30! Ridiculous! This hasn't been the last couple of nights, it's been a few weeks now; she normally goes down beautifully, but then has increasing and increasing the number of night wakings.
So what do you lot think can possibly be the problem and what the hell should I DO about it?! I won't do controlled crying, and I know pick up put down will just anger her more. I was thinking maybe shush pat in place of the hundreds of night feeds(?) but then somebody said that would be too much of a shock to her system suddenly being without the food?
And what about the evening crying til she's sick?! If this continues I think I'm just going to have to keep her up with us as it just doesn't feel right letting her get that upset. But does anybody have any ideas and WHY she suddenly seems to be traumatised by being put to bed? The only thing I can think is that we've only in the last couple of months been putting her down in the evening (used to keep her with us til we went to bed) and it obviously means she's been waking up and finding us gone (though I have a video monitor and rush in the second she MOVES so I'm at the door by the time the first cry comes) - do you think that could be it; she knows we're going to leave her? And if so, again, what on earth do I DO?!