Hi H.,
In my experience, there are set-back to the whole thing constantly. It isn't anything we do "wrong" and it really irritates me when people imply this.
Children go through growth spurs and changes, phisiological, psychological, emotional... as they comprehend the world they live in.
My daughter was taught to sleep in her bed for naps and bedtime around 8 months.
I could theorize in a million ways why this has changed over that time - she's 20 months now.
I blamed it on my MIL a few times, for I know she picked her up and brought her to bed with her. I know this is where it started ....
But, I gain nothing by placing blame.
Either way, since, she does what you're describing, she wakes up screaming at the top of her lungs (and I have an 8 month old too) and she'll scream for AN HOUR, 1am, 3 am, varies each time and just when I think we've tackled it and have continued to be consistant, it happens again.
My hubby and I made a rule, she's NOT getting picked back up again. We let her cry, he walks in and lays her back down once, if she freaks out, he won't go back in.
She will usualy drift back to sleep.
My Dr recommended going into her room and sitting there until she drifts back off but I said NO WAY, I have another baby and I have to get rest.
So, basically, we're letting her cry and drift back off. I try to explain it to her at night not to wake up crying, that she's safe. She has gotten much better. When she wakes up nicely, we give her a lot of praise, but she understands a lot more at 20 months.
Each person has to do what they need to for their specifi needs but I can tell you I am pretty confident most books, maybe with varied approaches, will tell you to let her CIO... and it DOES work, with consistency.....
I know its hard... I took a tylenol PM for a few nights and put in some thingys to muffle noise and I don't know if she cried, she was fine in her crib, but she hasn't done it in a few days since we decided to just let her cry ;)
I hope it is permanent!!