Don’t know what to do anymore!

My 9.5 month old has been a terrible sleeper since the day she was born. She slept in the bassinet for the first 7.5 months of her life (or on me). I transitioned her to the crib almost two months ago. Some nights are great. But most nights are like holy fuck how am I going to get through the night. (I also have three other kids) she just won’t stay asleep for more than three hours in the crib. And it’s normally from 815pm to about 10-30-1130pm. She’ll wake up screaming bloody murder and once I pick her up and sit down with her. She’ll settle back to sleep. But not into a deep sleep. I am able to once in awhile lay her back down and she’ll stay asleep a few more hours. But mostly. She’ll wake back up within the hour. The last few nights have been bad. So bad that I’m so tired that I just give in and let her sleep on me. But problem is I get zero sleep because she’s a tosser and a turner and weighs over 18 pounds. On top of that. I’m working on getting my 3 year old into her own bed and out of mine. I’ve even tried laying a shirt down in the crib that’s had my smell on it thinking that would help her. But nope. I’ve got white noise going every single night. I’m mentally and physically drained and just don’t know what to do anymore.