Help with getting toddler to sleep

I have a 1 month old and a 2 year old and I’m literally sitting in bed crying because my toddler has been tossing and turning for two hours and won’t sleep. Im so exhausted and she does this most nap times and most times going to bed at night. I literally don’t know what to do. She sleeps with us (by choice) but I’m just so sick of not getting any sleep and her tossing and turning on top of the regular newborn wake ups all night long. I don’t know if I’m looking for advice or support or both. I just don’t know what to do. I’m at my wits end. I’m so tired and exhausted. The biggest problem has always been getting to sleep. When she’s asleep she’s usually good all night. Any help or ADvice would be greatly appreciated. Maybe this is just a developmental stage? She turned two oct 13th. I just don’t know what to do. Thanks again.