9 Month Old Who Has Only Ever Coslept, Sleep Training is NOT WORKING

my husband and i have decided we need to do some sort of sleep training. our daughter has never been able to sleep independently. (she had reflux and a tongue tie so she had a lot of issues laying down on her back). so we’ve safely coslept since we left the hospital. co-sleeping literally saved us in the early days, and I really do love it. but now we’re 9 months in and our life is in a jumble.

naps are completely all over the place, sometimes 20 min sometimes 3 hours.

she can only fall asleep at night with me next to her, or else she wakes up within 30 min and is inconsolable until she's in my arms, which has resulted in her sleeping from 10/11pm-10am, because it's just impractical for me to get into bed sooner.

i am genuinely so exhausted and have never felt this depressed in my life. for a while I thought it was just PPD, but a friend of mine was in a similar boat and sleep-trained and felt so much better.

tonight we followed a sleep training guide that is basically the ferber method and she cried (wailed) for 50 min straight. not a single break or anything, no matter if my husband picked her up or patted her or anything. i finally caved and just nursed her because i couldn’t stand it anymore. we put her down in her crib when she finally nursed to sleep, but then she woke up screaming again 40 min later and was completely inconsolable until I nursed her.

most sleep training guides have intervals of when to go in and when to leave them, or to use verbal shushing or patting until they're not crying, but what if she is inconsolable for an hour with no end in sight????