I feel for you. I really do.
My middle DD arrived when DD1 was 11mo. She hated to sleep. She never napped - still doesn't. But, she wanted to stay awake until 11pm/midnight and then was up at 6am. Not cool when you're pregnant and sick and less cool when you have a newborn. DD2 slept through the night from the day she was born. I thought I had it made.
We let DD1 cry it out. We started a strict bedtime routine at 8pm and she was in her crib at 8:30pm. She cried for a week and then got over it and has been going to sleep at 8:30pm and, for the most part, sleeping through until 6am. Still not napping, but beggars can't be choosers, right? She didn't want to sleep in our bed. She just wanted to hang out. Watch TV with us. It wasn't that she wanted to co-sleep (she was in a co-sleeper, detached from the bed because I hated it attached, until about 6mo and then we moved her to her crib), she just wanted to be awake.
DD2...ya, she had us all FOOLED. She hit 7mo and holy heck broke loose and the girls hasn't slept more than 2hrs at a time since. She wakes up screaming every few hours and takes about half an hour to calm down and go back to sleep. Sometimes, I sit with her in her room. But, if she's especially loud, I take her in my room so she doesn't wake up her sister.
One night, a few months ago, I took her in my bed to see what went on. Sure enough, every few hours, she sat bolt upright and screamed at the top of her lungs. Then, she flopped around and I had to grab her to keep her from falling off my huge, king-sized bed. This went on all night long. I didn't sleep, obviously. Neither did she.
We're at the point where we're ordering a sleep study in a few months because something is not right. I average about an hour of sleep a day and it's really starting to take a toll on me.
DD1 cried it out and, within a week, slept fine. DD2....our attempts at CIO resulted in her slamming her head off the crib, throwing up all over herself, gasping for breath. Then, when she did fall asleep, she spent it curled into the fetal position and whimpering, just to snap awake and scream again.
We're kind of at a loss right now as to what to do. But, they want a sleep study done to see if it's night terrors (even though she's a little young for that) or something else. Apparently, if they diagnose her with something, my insurance covers a night nurse because I'm about to keel over.
You're not alone, if that's any consolation. If you want to PM me in the wee hours of the morning, I'm always up...on Facebook or playing some dumb computer game while I wait out the hour she sleeps until she starts screaming again.