I have a 10mo DD who until three weeks ago, was sleeping thru. She would go down about 6 and wake at 5.30. Routine was dinner, bath, bf then to bed and she would be awake when we put her down.
Then 3 weeks ago this stopped. She started waking in the night and not sure why. We would get her to sleep eventually by rocking and singing then as soon as we leave the room she wakes up and starts to wail. She's currently sleeping in her pushchair after wailing for 1 1/2 hours 
A couple of nights she's been up and playing at 1.30!!!! Sometimes boob helps but I'm cautious of starting night feeding again as it took ages to stop!
We are exhausted and would love any insight or advice