My baby is 9 and a half months old and over the last 2 months have got into a lovely routine of sleep. She could self settle. Lay her down at bedtime and walk out and she would fall asleep. The last two nights she has screamed for at least 30 minutes as soon as she is put down. I have checked for signs of teeth, ear infection etc. and it isn't that, I just don't know what to do. She gets beside herself and fights you when you try to comfort her, but works herself up more if you don't comfort her. It's making me really anxious and I'm dreading bed time.