hun, i have seen how alert and stubborn (in a good way) she can be, even when we take her for walks she's wide awake and taking everything in, most kids her age would fall asleep on a long walk.

I think it's a matter of do what you need to do, with Z i had a couple of stages where i would need to go and lay on the bed with her or tuck a top of mine under the sheet so she could 'smell' me, feed her to sleep in our bed and then slip out of the room.
It is a PITA and it's so very tiring but eventually it WILL pass, it's no comfort now i know but your trying and thats better than some.

Your always welcome here during the day but that wont help much at night... maybe you can get your OH to try giving her some expressed milk and a cuddle? get her a little more used to him and giving you a break?