DD is 15 months old and she has been a pretty good sleeper (we sleep trained with SE) up until she visited my parents for an overnight and her routine was completely out. She has also not been to daycare in a week and has been home with us all week as daycare is closed for Spring Break.
That being said, when we put her to bed and follow our usual routine, she has reverted back to screaming and crying like she did when we sleep trained.
We have gone back and are trying the SE stuff all over but, it is painful listening to her cry so hard...she is screaming and crying her lungs out right now...this is so painful to hear her

I don't think she is teething at the moment although she has not got her molars in yet but, when we have checked there is no sign of them at all.
We don't know what to do. Do we need to re-sleep train? Are we doing anything wrong? Is there anything else we should be doing? Or is this separation anxiety? Help please!