It's really rough, I know. I'm sorry to hear things haven't settled down at all.
I coped by doing whatever was easiest - bedsharing didn't improve my kids' sleep, but it meant I didn't have to get up, for eg - and otherwise only doing what is absolutely necessary. And yeah, taking whatever help I could - even one three-hour block of sleep in a week can make all the difference.
It was easier second time round because I knew from experience that it would eventually get better.