We've been through a variety of sleep dramas with our DD, so I'm always on the lookout for solutions. We've had similar to what you're describing, and took her out of the room and started again half an hour or so later with more success. With hindsight it's usually been related to teething or sickness or too much activity right before bedtime etc.
I've just been reading the no cry sleep solution for toddlers, which I'd highly recommend, and there are a number of changes I'm planning to make soon, primarily based around no longer feeding to sleep, which may be worth looking at. I expect it might be harder for a little while but hopefully easier in the long run.
I used to breastfeed on the bed lying down and then slid DD off and then gradually left the bed. We co-sleep so a Queen size gives ample room. I would try a toddler bed so she does not feel the movement and the loss of your body heat so quickly. We have only recently stopped bf to sleep but still stay with her holding her while she falls asleep. It is beautiful to watch her slowly slip into peaceful sleep land.
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